MMH900 Series Statistical Multiplexer User Guide
User Guide S000315A Revision A MultiMux (#MMH904Ca) (#MMH908Ca) This publication may not be reproduced, in whole or in part, without prior expressed written permission from Multi-Tech Systems, Inc. All rights reserved. Copyright © 2003, by Multi-Tech Systems, Inc. Multi-Tech Systems, Inc. makes no representations or warranties with respect to the contents hereof and specifically disclaims any implied warranties of merchantability or fitness for any particular purpose. Furthermore, Multi-Tech Systems, Inc.
Contents Chapter 1 - Introduction & Description ................................ 8 1.1 Introduction .................................................................................... 9 1.2 About This Manual ......................................................................... 9 1.3 Background ................................................................................... 11 1.3.1 Description of Statistical Multiplexing ................................... 12 1.3.1.1 Statistical Multiplexing ..
Chapter 3 - Front & Rear Panel Descriptions..................... 34 3.1 Introduction .................................................................................... 35 3.2 Front Panel .................................................................................... 35 3.3 LED Indicators .............................................................................. 36 3.4 Back Panel .................................................................................... 40 3.4.1 ON/OFF Switch ....
.2.7 5.2.8 5.2.9 Internal Composite Link DSU Commands ............................ 86 Test Commands ................................................................... 87 Command Modem commands ............................................. 89 Chapter 6- Operating Procedures ....................................... 90 6.1 Introduction .................................................................................... 91 6.2 MultiMux Operating Procedures .................................................
Appendix C .............................................................................................. 121 Cabling Diagrams .............................................................................. 121 Appendix D .............................................................................................. 125 Command Modem Commands ......................................................... 125 Appendix E Command Modem S-Register Function .............................. 138 Appendix F ................
Chapter 1 - Introduction & Description
Chapter 1 - Introduction & Description 1.1 Introduction Congratulations! Your new MultiMux MMH900 series is one of the finest statistical multiplexers on the market today. The MultiMux is completely software driven and is controlled by you through its command port. This gives you great flexibility and ease of operation. This Owner’s Manual will help you to install and use your MultiMux, and also provide you with a valuable information resource in the future.
Chapter 1 - Introduction & Description Chapter 3 - Front and Rear Panel Descriptions Chapter 3 describes the front panel indicators, the switches and jumpers within the cabinet and the rear panel connections. The front panel indicators are described in the various groups depending on the configuration of the MultiMux. Indicator groups are active depending on how the MultiMux is used. The front panel is the same for all models and contains some indicators for future enhancements.
Chapter 1 - Introduction & Description 1.3 Background Any data communications environment that has more than one asynchronous line going between common locations can probably benefit by installing a pair of statistical multiplexers (stat muxes). A stat mux performs the function of combining several asynchronous data communication channels into one composite signal that can be transmitted between two locations more inexpensively than the cost of the individual lines.
Chapter 1 - Introduction & Description on one end of the link and then broken up into individual components on the other end. Someone wishing to "tap" into a muxed signal must not only have the link protocol which is typically a proprietary version of High Level Data Link Control (HDLC), but must also know the individual channel assignment schemes and data formats. 1.3.
Chapter 1 - Introduction & Description 1.3.1.2 Communications The basic functions of multiplexing are to make communications more efficient, to provide a means of improving accuracy of asynchronous communications by using synchronous techniques, and to improve data security by encrypting several data streams into one coded link. The channel devices can be any asynchronous RS232 compatible units, from “dumb terminals” to personal computers running asynchronous communications software.
Chapter 1 - Introduction & Description 1.4 Product Description There are two basic models of MultiMux MMH900 series available: a four channel and eight channel units with internal command modem, optional composite link modems and a command port. The four channel MultiMux MMH904 connects four async devices to asynchronous channels that transfer data at a channel speed of up to 38.4K bits per second (bps). The eight channel MultiMux MMH908 connects eight async devices.
Chapter 1 - Introduction & Description channel devices and the composite link. The async devices are connected to CHANNEL 1 through CHANNEL 4 connectors on the back panel of the MultiMux MMH904 with an RS232 cable. The MultiMux MMH908 has four additional channel connectors for connecting up to eight devices. A number of internal and external composite link devices can be used to connect the MultiMux to the PDN. The MMH900 series has an internal 28,800 bps composite link modem or an internal 56,000 bps DSU.
Chapter 1 - Introduction & Description The composite link has to be configured for its parameters before data can be transferred. The composite link parameters are determined by more than just AT commands transferred to the command processor. The composite link parameters are determined by what type of device is used, whether it is internal or external, speed, what type of remote multiplexer we are communicating with and a number of line conditioning parameters.
Chapter 1 - Introduction & Description 1.5 System Features 1.5.1 Response Time Control Response time control is the technique used by a mux to make sure that no user experiences undue delays in performance due to a specific channel using too much link time. This can occur if one of the channels is performing a high volume batch function, such as a print dump or program transfer. There are a variety of priority control (response time) schemes in use by different mux vendors.
Chapter 1 - Introduction & Description 1.5.3 Flow Control Flow control regulates the volume of data entering the buffers. When a particular channel buffer is almost full, a flow control command is issued which stops further activity until the buffer is emptied. The most common flow control methods currently used are Xon/Xoff, RS232C signal control (using DTR or CTS) and ENQ/ACK. The MultiMux supports all three.
Chapter 1 - Introduction & Description 1.5.6 Operational Statistics and AutoReporting Operational statistics provides the activity report for the MultiMux network, and Auto-Reporting provides a means to report on these statistics through the supervisory console on a set periodic time cycle. Statistics such as receive-block errors pinpoint modem or line problems, and flow control time totals indicate channel devices being set at excessive speeds.
Chapter 1 - Introduction & Description 1.5.10 Composite Link The composite link of the MultiMux is capable of synchronous, asynchronous and digital communications. The MultiMux can be connected to several different types of communications links through various modems and DSUs connected internally and externally. Internally the MultiMux can be configured with synchronous lease line modem at a link speed up to 28.8K bps or a Data Service Unit (DSU) at link speeds up to 56K bps.
Chapter 1 - Introduction & Description 1.6 FCC Regulations for Telephone Line Interconnection 1. This equipment complies with Part 68 of the FCC rules. On the outside surface of this equipment is a label that contains, among other information, the FCC registration number and ringer equivalence number (REN). If requested, this information must be provided to the telephone company. 2. As indicated below the suitable jack (USOC connecting arrangement) for this equipment is shown.
Chapter 1 - Introduction & Description 8. This equipment cannot be used on public coin service provided by the telephone company. Connection to Party Line Service is subject to state tariffs. (Contact the state public utility commission, public service commission or corporation commission for information.) 9. If required, this equipment is hearing aid compatible. Manufacturer: Model Number: FCC Registration No.: Ringer Equivalence: Modular Jack (USOC): Service Center in USA: Multi-Tech Systems, Inc.
Chapter 1 - Introduction & Description 1.7 DOC Terminal Equipment Notice: The Canadian Department of Communications label identifies certificated equipment. This certification means that the equipment meets certain telecommunications network protective, operational and safety requirements. The department does not guarantee the equipment will operate to the user’s satisfaction.
Chapter 1 - Introduction & Description 1.8 Specifications 1.8.1 Channels Number of Channels Up to four (#MMH904), or up to eight (#MMH908) Maximum Speed 38,400 bps All Channels Channel Speeds All standard speeds from 150 bps to 38.4K bps Data Format Asynchronous: 5, 6, 7, or 8 data bits, with 1,1.
Chapter 1 - Introduction & Description Diagnostics 1.8.3 Memory test, Analog Loop, Digital Loop, Remote Analog Loop, Switch test, LED test, Non-Volatile RAM test, Watchdog Timer Composite LInk Data Format Synchronous or Asynchronous Link Speeds Up to 128,000 bps Link Protocol Proprietary modified HDLC Error Correction 16-bit CRC block check with ARQ Interface RS232C/CCITT V.35/V.24, or use MultiMux integral modem or DSU 1.8.4 33,600 bps Link Modem Modulation ITU-T V.34; AT&T V.
Chapter 1 - Introduction & Description 1.8.6 ISDN Terminal Adapter Description Integral ISDN terminal adapter card Operating Mode ISDN Basic Rate; 1B+D or 2B+D Synchronous Data Rates 2.
Chapter 2 - Configuration
Chapter 2 - Configuration 2.1 Introduction The MultiMux MMH900 Series is available in two models; the four and eight channel units with an internal command modem, a composite link modem or DSU, dial-up capability from a remote location into the command modem and a command port for local AT command configuration information.
Chapter 2 - Configuration 2.2 Configuration 1 Configuration 1 is two Multi-Tech MultiMux MMH904Ca/144 which are four channel multiplexers with internal 28.8K bps composite link modems linking sites one and two over a 4-wire analog lease line. The local site has the MMH904Ca/288 connected to a host minicomputer. The remote site has three terminals and a shared printer connected to the asynchronous channels of the remote mux.
Chapter 2 - Configuration Local Channel Parameter CHN 01 02 03 04 SPD WORD 19200 8 19200 8 19200 8 19200 8 STP BIT 1 1 1 1 PARITY NONE NONE NONE NONE FLOW CONTROL XON/XOFF XON/XOFF XON/XOFF XON/XOFF ENQ/ ACK OFF OFF OFF OFF ECHO OFF OFF OFF OFF PACE OFF OFF OFF OFF PASS EIA OFF OFF OFF OFF PASS XON OFF OFF OFF OFF OK Configuration 1 Local Site Channel Parameters Local Channel Parameter CHN 01 02 03 04 SPD WORD 19200 8 19200 8 19200 8 19200 8 STP BIT 1 1 1 1 PARITY NONE NONE NONE NONE FLOW CON
Chapter 2 - Configuration 2.3 Configuration 2 Configuration 2 is two MultiMux MMH904Ca four channel multiplexers with two external Multi-Tech MultiModemII MT2834BLs linking the two sites over an async dial-up line. The MultiModemII's are connected to the dial-up line and the RS232C interface from the modems is connected to the EXTERNAL COMPOSITE LINK connector on the back panel of the MMH904Ca's. The MH904Ca's are set up for an external link device with a maximum link speed of 57,600 bps.
Chapter 2 - Configuration 2.4 Configuration 3 Configuration 3 is two MultiMux MMH908Ca/56 eight channel multiplexers connecting a minicomputer at the local site to eight remote terminals over a digital composite link. The MMH908Ca/56s have internal 56K bps Digital Service Units (DSUs) tieing the MultiMuxes to the Digital Data Service (DDS) network provided by your teleco facility.
Chapter 2 - Configuration Configuration 3 Composite Link Configuration Local Channel Parameter CHN 01 02 03 04 05 06 07 08 SPD WORD 19200 8 19200 8 19200 8 19200 8 19200 8 19200 8 19200 8 19200 8 STP BIT 1 1 1 1 1 1 1 1 PARITY NONE NONE NONE NONE NONE NONE NONE NONE FLOW CONTROL XON/XOFF XON/XOFF XON/XOFF XON/XOFF XON/XOFF XON/XOFF XON/XOFF XON/XOFF ENQ/ ACK OFF OFF OFF OFF OFF OFF OFF OFF ECHO OFF OFF OFF OFF OFF OFF OFF OFF PACE OFF OFF OFF OFF OFF OFF OFF OFF PASS EIA OFF OFF OFF OFF OFF OFF OFF
Chapter 3 - Front & Rear Panel Descriptions
Chapter 3 - Front & Rear Panel Descritpions 3.1 Introduction This chapter describes all of the front panel LEDs, switches, jumpers and the shunt on the base and the back panel connectors. The front panel contains all the LEDs for all the MultiMux MMH900 Series models. Some of the LEDs on your particular model will not be active, for example, if you have an internal composite link modem, the External Composite Link LEDs on the lower left side of the control panel will not light.
Chapter 3 - Front & Rear Panel Descritpions 3.3 LED Indicators Command Modem Indicator Description CD Indicates the local command modem has detected a carrier signal from a remote modem. RCV/XMT Indicates that the command modem is on-line by flashing with data activity between the two command modems. OH Indicates that the dial-up line for the command modem is off-hook. DTR Indicated that the command modem is ready to communicate.
Chapter 3 - Front & Rear Panel Descritpions Channel Indicator Description Channel 1-8 The Channel Receive (RCV) and Transmit RCV/ XMT(XMT)indicators show the activity level on each channel.MultiMux MMH904 uses Channel One through Channel Four indicators. The MultiMux MMH908 can connect up to eight async devices which use Channel One through Channel Eight indicators.
Chapter 3 - Front & Rear Panel Descritpions Internal Composite Link (DSU) Indicator Description CD The Carrier Detect (CD) indicator lights when the composite link DSU detects a carrier signal from the remote MultiMux. XMT The Transmit (XMT) indicator flashes as data is being transmitted to the remote multiplexer on the composite link. RCV The Receive (RCV) indicator flashes as data is being received from the remote multiplexer on the composite link.
Chapter 3 - Front & Rear Panel Descritpions RCV The Receive (RCV) indicator flashes as data is being received by an internal composite link 9600 or 14,400 bps modem from a remote multiplexer. CTS The Clear To Send (CTS) indicator lights when an internal composite link 9600 or 14,400 modem is ready to transmit data. Internal Composite Link (ISDN) Indicator Description CD The Carrier Detect (CD) indicator lights when the terminal adapter establishes a connection with the remote unit.
Chapter 3 - Front & Rear Panel Descritpions 3.4 Back Panel The cable connections for the MultiMux are made at the back panel. Refer to Chapter 4 for cabling installation procedures. Refer to Appendix C for cabling diagrams. The MultiMux back panel is shown in Figure 3-2. I COMMAND PORT CHANNEL 8 CHANNEL 7 CHANNEL 6 CHANNEL 5 CHANNEL 4 CHANNEL 3 CHANNEL 2 CHANNEL 1 O COMMAND MODEM DIAL-UP COMPOSITE LINK INTERNAL DIAL UP LEASED MODEM DIGITAL DSU EXTERNAL RS232C/V.35 Figure 3-2.
Chapter 3 - Front & Rear Panel Descritpions 3.4.6 COMPOSITE LINK INTERNAL MODEM LEASED Connector This connector is used when the MultiMux MMH900 series is connected to a lease line with an internal Multi-Tech 9600, 14.4K, or 28.8K bps modem installed. The composite link internal modem leased connector provides an RJ11 connection. 3.4.
Chapter 3 - Front & Rear Panel Descritpions 3.5 Switches/Jumper/Shunt Switch settings can be changed by taking off the front panel. To change the RKWL/144 jumper, V.24/V.35 shunt, V.29/V.33 shunt, or the 2834 shunt, the front panel and top cover need to be removed. The switches, jumper and shunts are shown on the base in Figure 3-3. V.35 Shunt V.35 V.24 Shunt V.24 V29/V33 2834 OTHER 1 2 3 4 5 RKWL14.
Chapter 3 - Front & Rear Panel Descritpions With an MMH904 Unit C = Closed Channel # O = Open (Up) 1-4 5-8 9-12 13-16 17-20 21-24 25-28 29-32 Switch Position 6: C O C O C O C O Switch Position 7: C C O O C C O O Switch Position 8: C C C C O O O O With an MMH908 Unit Channel # 1-8 9-16 17-24 Switch Position 6: C O C O Switch Position 7: C C O O Switch Position 8: C C C C 3.5.
Chapter 3 - Front & Rear Panel Descritpions 3.5.3 144RKWL/OtherJumper The 144 RKWL/OTHER jumper is positioned in the 144RKWL (Rockwell) position when a 14,400 Rockwell internal composite link modem is used. When any other internal composite link modem or DSU is used, this jumper is in the OTHER position. The location of the jumper on the base is shown in Figure 3-3 and the placement of the jumper is shown in Figure 3-4.
Chapter 4- Installation
Chapter 4 - Installation 4.1 Introduction This chapter explains how to unpack and install your MultiMux cabinet. 4.2 Safety Warnings 1. Never install telephone wiring during a lightning storm. 2. Never install telephone jacks in wet locations unless the jack is specifically designed for wet locations. 3. Never touch uninsulated telephone wires or terminals unless the telephone line has been disconnected at the network interface. 4. Use caution when installing or modifying telephone lines. 5.
Chapter 4 - Installation 4.4 Installation Table 4-1. Installation Procedure Composite Link Installation 1 MultiMux has an internal link modem and are connecting to a dial-up service: Connect the RJ11 cable to the COMPOSITE LINK INTERNAL MODEM DIAL-UP connector on the back panel of the MultiMux and your phone line.
Chapter 4 - Installation External modem with V.35 interface is being connected: Remove the top cover and move the V.24/V.35 shunt from the V.24 position to the V.35 position. Replace the top cover. V.35 Shunt V.35 V.24 Shunt V.24 V29/V33 MultiTech Systems OTHER 1 2 2 3 4 5 6 7 8 MMH956 2834 V.29/V.33 Shunt RKWL14.4 1 2 3 4 2834 Shunt Figure 4-2. Shunts Connect the AC power cord shipped with your MultiMux to the AC power connector on the back panel and to the AC outlet.
Chapter 4 - Installation Supervisory Console 5 If you are connecting a supervisory console to the MultiMux, connect a terminal or PC to the COMMAND PORT connector via an appropriate RS232C cable. The PC needs to be running communications software. Note: Any cables connected to the computer should be shielded to reduce interference.
Chapter 4 - Installation Channel 8 Route and connect your channel devices to the MultiMux back panel CHANNEL 1 - CHANNEL 4 on a MultiMux MMH904 or CHANNEL 1 - CHANNEL 8 on aMultiMux MMH908 connectors using RS232 cables. Do this at both of your sites, so that channel 1 at one site communicates with channel 1 at the other site, and so on. Note: Any cables connected to the computer should be shielded to reduce interference.
Chapter 4 - Installation As you change operational parameters, they will not actually be incorporated into your running system until you execute a Store New Parameters (&W) command.
Chapter 5 - Commands
Chapter 4 - Installation 5.1 Introduction This chapter presents a command summary followed by a detailed description of each command used in the MultiMux. The structure of the commands is that they all begin with the prefix AT. Each command line may contain any number of commands in a string (no spaces) up to a limit of 40 characters. Most commands include a value and are part of the 40 character total.
Chapter 5 - Commands Table 5-1. Command Summary (cont.
Chapter 5 - Commands Table 5-1. Command Summary (cont.) TYPE COMMAND DESCRIPTION Channel R0-3 Response Time Priority Parameter SB1 Stop Bit 1 SB1.5 Stop Bit 1.
Chapter 5 - Commands Table 5-1. Command Summary (cont.) TYPE COMMAND DESCRIPTION Internal 9600/14.
Chapter 5 - Commands Table 5-1. Command Summary (cont.
Chapter 5 - Commands 5.2 Command Description The following command descriptions explain the effect that executing each command has on your MultiMux network. Refer to Chapter 6 for instructions on how to execute the commands. 5.2.1 Z General Commands Reset The Reset command will set the operating parameters of the MultiMux to its most recently stored values. Executing the Reset command performs the same function in the logic as turning power off and then on to the unit.
Chapter 5 - Commands The H command menu is as follows: General Help - Each command line must begin with the prefix AT. - Each command line may contain any number of commands up to 40 characters total. - Most command letters must be followed by a value. - For help on specific commands, enter "ATH" followed by one of the command letters. ATH1 for channel parameter commands. ATH2 to view the DIP switch configurations. ATH3 for async and sync composite link format commands.
Chapter 5 - Commands The H1 Menu is as follows: CHANNEL PARAMETER COMMANDS B BAUD RATE SELECTION P PARITY SELECTION C CHANNEL SELECTION R RESPONSE TIME PRIORITY DC DEST. CHANNEL SELECTION SB STOP BIT SELECTION DN DEST.
Chapter 5 - Commands The H2 Menu is as follows: MULTIMUX Eight Position DIP-Switch Definitions and Settings Switch 1 Initiate Dwn Line Load Switch 2 Link Device Switch 3 8/4 Channel UP = ON DN = OFF INTERNAL EXTERNAL 8 CHAN 4 CHAN CURRENT SETTINGS: DN 1-4 SW#6 DN SW#7 DN SW#8 DN 1-8 SW#6 DN SW#7 DN SW#8 DN DN 5-8 UP DN DN 9 - 16 UP DN DN Switch 4 Remote Access Switch 5 Not Used SEE TABLE BELOW ENABLED DISABLED DN 9 - 12 DN UP DN 17 - 24 DN UP DN Switch 6, Switch 7, Switch 8 Channel Group Selec
Chapter 5 - Commands The H3 Mend is as follows: COMPOSITE LINK FORMAT COMMANDS #EOFR - SELECTS RECEIVE END OF FRAME CHARACTER FOR ASYNC LINK. #EOFT - SELECTS TRANSMIT END OF FRAME CHARACTER FOR ASYNC LINK. $MUXCL - SELECTS INT/EXT CLOCKING OF MUX COMPOSITE LINK. $MUXSP - SELECTS SPEED OF MUX COMPOSITE LINK WHEN MUX CLOCKING IS INTERNAL OR ASYNC LINK IS SELECTED.
Chapter 5 - Commands #S STATUS REPORTING #S9 STATUS OF FRONT PANEL LEDS For HELP on a specific command, enter “ATH” followed by a command letter. The H5 Menu is as follows: MISCELLANEOUS COMMANDS I ID CODE #MA MODEM ACCESS FOR COMMAND MODEM #RA REMOTE ACCESS FOR COMMAND MODEM &T TEST MODES &W SAVE PARAMETERS "WRITE TO MEMORY" Z RESET MULTIMUX For HELP on a specific command, enter “ATH” followed by a command letter.
Chapter 5 - Commands The H7 Menu is as follws: INTERNAL DSU COMMANDS #DSUCL SELECTS CLOCKING FOR INTERNAL DSU. #DSUSP SELECTS SPEED FOR INTERNAL DSU. For HELP on a specific command, enter “ATH” followed by a command letter. The H8 Menu is as follows: INTERNAL MMH2834 COMMANDS $M(ASYNC/SYNC) SYNC OR ASYNC.
Chapter 5 - Commands 5.2.2 Channel Parameter Commands Command Description BO Channel Off Command The channel off command turns the selected channel off. This command turns off a particular channel or all channels depending on the command. This allows the more efficient use of the dynamically allocated buffers and allows the multiplexer to skip the scanning of unused channels. Bxxxx Baud Rate Select The Bxxxxx command selects the bps rate on the indicated channel.
Chapter 5 - Commands communicate with one other channel. On multinode networks, this command must be entered at both channel locations specifying each other as destinations (channels can pass through two nodes to get to its destination). On point-to-point networks, this parameter can be downline loaded. DNxx Destination Node Number This command is not necessary when a MultiMux 900 Series is connected to another MultiMux 900 Series.
Chapter 5 - Commands keep up with the volume of data sent to it. There are two types of flow control available on the MultiMux. The software based Xon/Xoff and hardware based Clear to Send (CTS). F0 turns flow control off, F1 selects CTS flow control, and F2 selects Xon/Xoff flow control. The way channel devices control the data flow to them from the MultiMux is called Pacing (see Pacing command).
Chapter 5 - Commands channels to receive EIA control signals through the MultiMux. Since in normal interactive operations, the existence of a multiplexer should be transparent to individual users, the Pass EIA Signals command will allow terminals to operate as if they were connected directly to a communications line and not through a multiplexer. This is done by allowing selected pins (signals) on one mux to be passed through to selected pins (signals) on a second remote mux.
Chapter 5 - Commands F-11-F12 Inverted DTR The Inverted DTR Commands (F11 and F12) work in conjunction with Pacing Control and change the way the MultiMux reacts tothe DTR signal. With Xon/Xoff Flow Control and Pacing, you will end up with Xon/Xoff Pacing, and with CTS Flow Control plus Pacing, data flow will be controlled by the presence of the DTR (pin 20) signal on the RS232 interface. F11 turns on Inverted DTR so that a high signal stops data flow and a low starts data flow.
Chapter 5 - Commands console as shown in the following example. To display the parameters for an individual channel, say channel three, you would enter ATL3 and hit your Return key.To display the parameters for all of the channels, enter ATL0 and then hit your Return key.
Chapter 5 - Commands use an R0 setting. If the mux is configured mainly for interactive users, R0 is the best setting. SB1,SB1.5, SB2 Stop Bits The Stop Bit commands set the number of stop bits used in asynchronous characters. The default condition is one stop bit SB1. An SB1 command sets one, an SB1.5 command sets 1.5, and an SB2 command sets two stop bits. SN Source Node Number This command is not necessary when a MultiMux 900 Series is connected to another MultiMux 900 Series.
Chapter 5 - Commands &F Load Factory Parameters The factory default command resets the MultiMux parameters to their original factory settings.
Chapter 5 - Commands #S1-S8 Channel Status The Channel Status command displays the individual channel percentage activity levels and signal pin status. The status message is displayed in the following format.
Chapter 5 - Commands 5.2.3 Composite Link Commands The Composite Link commands perform the function of a system monitor. In addition to displaying the information available on the MultiMux’s LED display, they also provide additional network statistical information. The purpose of the commands are to allow network monitoring via the supervisory port as an alternative to viewing the LED indicators.
Chapter 5 - Commands 10 msec and #FT1 sets the flush time value to 20 msec. The default is #FT0. $L List Composite Link Configuration The List Composite Link Configuration command causes the MultiMux to display its internal composite link parameters on the supervisory console. Five different parameter displays can be shown depending on the internal composite link device. The first example shows the default parameters for a 9600 bps internal modem. Example two shows the 14.4K bps internal modem.
Chapter 5 - Commands conditions that affect the link's operation, such as the downline load, modem type, flush timer value and the response time setting. Local MultiMux Composite Settings INIATE DOWN LINE LOAD TYPE OFF #RB MODEM FLUSH TIMER TIME INTERNAL 10ms RESPONSE 3 Status Report Baud Rate This command sets the baud rate of the status report generated by the #S0 command on the system supervisor console display.
Chapter 5 - Commands #S0 Composite Link Status Report This command generates a status message for display on the system supervisor console display. The message is in the following format: COMPOSITE STATISTICS ELAPSED TIME : BLOCKS TRANSMITTED : RETRANSMITS : BLOCKS RECEIVED : RECEIVE BLOCK ERRORS : LINK ALARMS : REMOTE DOWNS : RECEIVE FLOW CONTROL TIME : AUTOMATIC REPORTING : #S9 00 DAYS 00 HRS 00 HRS 00 MIN OFF 19200 00 MIN. 0 0 0 0 0 0 00 SEC.
Chapter 5 - Commands 5.2.4 #EOFR Composite Link Format Commands Receive End Of Frame Character The Receive End Of Frame character lets the MultiMux accept an End of Frame character when the composite link is in Async mode. When the composite link is in async mode, the #EOFRxx command determines the End of Frame character by the hexadecimal value of xx. The Receive End of Frame Character should only be set under the direction of Tech Support.
Chapter 5 - Commands $MUXB $MUXSP 2400 $MUXSP 4800 $MUXSP 7200 $MUXSP 9600 $MUXSP 14400 $MUXSP 19200 $MUXSP 38400 $MUXSP 57600 $MUXSP 64000 $MUXSP 76800 $MUXSP 115200 $MUXSP 128000 MUX BACK-TO-BACK The Mux Back-to-Back ($MUXB) command is only used during testing of the composite link when the back-to-back cable is connected between two MultiMuxes. The default value is ($MUXB0) and is used during normal operation.
Chapter 5 - Commands The #CLA0 disables access from the command port to the composite link. The default condition is no access to the composite link thru the command port. #DTR Toggle DTR The Toggle DTR command (#DTR) drops DTR for 500 msec on the composite link. The Toggle DTR command is used for DTR dialing with an external dial-up modem.
Chapter 5 - Commands 5.2.5 Command $MC Internal 9600/14.4K Composite Link Modem Commands Description Modem ConfigurationSelect This command configures the operations speed at which the internal composite link modem will operate. The possible configurations are as follows. $EP0-2 9600 bps Modem 14.4 Kbps Modem $MC0: V.29/9600 bps $MC1: V.29/7200 bps $MC2: V.29/4800 bps $MC0: $MC1: $MC2: $MC3: $MC4: V.29/9600 bps V.29/7200 bps V.29/4800 bps V.33/14400 bps V.
Chapter 5 - Commands $LD0-2 $LA0: Off (default) $LA1: Japan Level $LA2: U.S. Level Link Delay This command enables cable equalization that compensates for delay distortion in the public telephone network in a similar manner to the amplitude done by the Link Amplitude command. $CQ0-3 $LD0: Off (default) $LD1: Japan Level $LD2: U.S.
Chapter 5 - Commands The Receive Level settings are as follows: $RL0: -43 dbm (default) $RL1: -26 dbm $TL0-7 Transmit The Transmit Level Command selects the level of the modem Level output transmissions. The closer the transmit level is to zero the greater the level (strength) of the output signal. This parameter should only be changed under the direction of service personnel. The default condition for the transmit level is 0 dbm.
Chapter 5 - Commands 5.2.6 Internal MMH2834 Modem Configuration Commands The internal MMH2834 modem configuration commands configure the composite link for the internal MMH2834 modem. Additional commands for setting up the modem are provided in Appendix J. Command Description $M Internal MMH2834 Modem Sync/Async Mode (ASYNC/SYNC) The sync or async mode of the MMH2834 modem is enabled by the $M(ASYNC/SYNC) command.The $MSYNC command places the MMH2834 modem in sync mode.
Chapter 5 - Commands $M, #M Internal MMH2834 Modem Lease LIne Answer/ Originate Mode The Answer/Originate Mode $M (Answer/Originate) command sets the leade line frequency for the MMH2834 modem originating a call and the remote MMH2834 that is receiving the call. The #M(Answer) command places the MMH2834 in answer mode. The default mode for the MMH2834 is answer mode.
Chapter 5 - Commands 5.2.7 Internal Composite Link DSU Commands Command Description $DSUCL DSU Clock The DSU Clock command allows the internal DSU to accept timing from it's internal timing oscillator ($DSUCLI) or from the DDS Network's Receive Bipolar Signal. DDS Clocking command ($DSUCLD) is used whenever the internal DSU is connected to DDS network line. The $DSUCLD command is the factory default and automatically configures the MultiMux clocking.
Chapter 5 - Commands 5.2.8 Test Commands Command Description &T1-2 MemoryTest There are two memory tests available on the MultiMux. The first test (&T1) will alter the contents of the basic system memory, which is automatically restored when power is turned on to the system or when a reset command is executed. The second memory test (&T2) alters the contents of the memory that stores parameters. When this test is executed, a warning is given that stored parameters will be destroyed.
Chapter 5 - Commands &T6 Test Mode 6 Test Mode 6 is the Remote Analog Loop test which causes any data from the composite link to be echoed through just the analog half of the internal modem back to the link. The function of this command is similar to Test Mode 5 except it checks only the modem’s analog circuitry. This test is not used if your MultiMux is configured with a DSU. &T7 Test Mode 7 Test Mode 7 is the Switch and LED operational test.
Chapter 5 - Commands 5.2.9 Command Modem commands The command modem select and remote access commands are described in this section. Additional command modem AT commands are provided in Appendix D. Command #MA Description Command Modem Select The Command Modem Select command (#MA1) sends all subsequent commands generated on your supervisory console to the command modem. The various commands for the command modem are AT command set compatible with those described in Appendix D.
Chapter 6- Operating Procedures
Chapter 5 - Commands 6.1 Introduction The following procedures assume that your MultiMuxes (local and remote) have been installed properly and the appropriate channel devices have been connected to each channel. 6.2 MultiMux Operating Procedures The MultiMux operating procedures cover entering parameters for both your local and remote MultiMux units. Table 6-1. MultiMux Operating Procedures Channel 1 Turn power on to your MultiMux and supervisory console, type AT and then hit Return.
Chapter 5 - Commands Table 6-1. MultiMux Operating Procedures (cont.
Chapter 5 - Commands The following will be displayed on your system monitor if your MultiMux is configured with an internal composite link DSU: LINK LINK DSU DSU EOF XMT EOF RCV LOOP DEVICE FORMAT SPEED CLOCKING CHARACTER CHARACTER BACK DSU SYNC 56000 DSU N/A N/A OFF If the internal composite link modem is either a V.34/28800, the INTERNAL LINK DEVICE Modems MMH2834 LED on the front panel is ON.
Chapter 5 - Commands 7 To reconfigure a channel based on your actual channel requirements, enter commands as described in Chapter 5 or Appendix D of this manual. To save new parameters, you must again execute an AT&W command. Downline Load 8 If you are downline loading remote parameters, your 8-position DIP switch SW1 must be in the UP (open) position, refer to the 8-position DIP Switch in the Configuration Chapter (Chapter 3) of this manual.
Chapter 5 - Commands 6.3 Command Modem Operating Procedures A wide variety of autodial operations and modem options can be controlled when the command modem is in the command mode. Command modem access commands are described in Chapter 5. Appendix D describes the general AT commands in detail. Table 6-2. Command Modem Operating Procedures 1 Your supervisory console must be set to 2400 bps or less to communicate with the command modem.
Chapter 5 - Commands dialing commands. For example, enter the following to dial a phone number (555-1212) through a switchboard. ATD9,5551212 (hit Return) When a carrier signal is detected, the Connect (1) Result Code is displayed. If no carrier is detected, the No Carrier (3) Result Code is displayed after about 30 seconds. 4 You are now communicating with your remote MultiMux. Any commands you now execute will be done by the remote unit.
Chapter 7 - Troubleshooting
Chapter 6 - Operating Procedures 7.1 Introduction The MultiMux is designed to make it easy to operate and maintain. The procedures in this chapter will help isolate any problems you have to a specific component of your network, at which point you will be instructed to call the appropriate personnel or execute commands to adjust operating conditions. There are no specific repair procedures besides command execution and switch settings that you are expected to perform in MultiMux maintenance.
Chapter 6 - Operating Procedures retransmits needed to get the data through can indicate a line problem. Comparing the blocks received and receive block errors indicates the same problem from the other end of the link. The comparative numbers that you might encounter could be 10,000 blocks transmitted (or received) with 500 or 1000 retransmits (or receive block errors). Link Alarms simply tell you that there are some sort of problems on the link.
Chapter 6 - Operating Procedures If you have any problems in performing these procedures, contact the Tech Support department for assistance, refer to Chapter 8. Using the Test Cable MultiMux Test Cable MultiMux Internal Composite Connector Note: Used locally before installation to verify operation of entire system except compolsite link.
Chapter 6 - Operating Procedures 7.4 Troubleshooting Guide The following guide is set up as a series of possible conditions, causes and suggested fixes or steps in finding the failing unit. Because of the different manufacturer’s equipment involved in typical multiplexer networks, you may encounter “finger pointing” as to who is at fault. Who is at fault is not as important as getting you back on line as soon as possible.
Chapter 6 - Operating Procedures Table 7-1.
Chapter 6 - Operating Procedures Supervisory Console not communicating with mux command port Problem Communications softwarenot installed on Supervisory Console Solution 1. Install communications software on supervisory console, refer to communicaitons software user’s manual for installation. Problem Bad cable or cable connection Solution 1.
Chapter 6 - Operating Procedures Composite link down with CTS, XMT and REMOTE DWN LEDs ON Problem Composite Link cabling Solution 1. If internal composite link modem is installed, check Composite Link cabling for loose connection. 2. If external composite link modem is installed, check composite link cable for loose connection or bent pin. Problem Not receiving data from remote mux Solution 1. Verify that both muxes are powered ON. 2. Verify that both muxes are connected to communications line. 3.
Chapter 6 - Operating Procedures Composite link down with CO CTS and REMOTE DWN LEDs ON Problem External modem settings on remote mux Solution 1. Verify that external modem is set for sync, full duplex and internal clocking. 2. Connect composite link cable between mux and modem. Composite link and all channels down with REMOTE DWN and all channel RCV LEDs ON Problem Mux memory failure Solution 1. Enter L and recore all channel parameters before running memory test.
Chapter 7 - Troubleshooting Procedures Problem Channel devices incorrectly cabled Solution 1. Refer to cabling diagrams of both mux and channel devices. Some channel devices not communicating with MultiMux and composite link up Problem Incorrect channel parameter settings fo rthose channel devices Solution 1. Verify channel parameter settings for those channel devices, refer to Lx command in Chapter 4 to display channel parameters. 2.
Chapter 7 - Troubleshooting Procedures 7.5 Channel Device Testing The first step in system testing is to check the operation of the multiplexer network section from each channel device to the MultiMux and back again to the channel device. These procedures will enable you to see that data from the channel device is passing through the MultiMux properly by echoing channel keystrokes through the MultiMux and then displaying them as correct characters on the channel device’s monitor. Table 7-2.
Chapter 7 - Troubleshooting Procedures 7.6 Local Modem and Communications Line Testing After determining that the channel-device-to-MultiMux portion of the multiplexer network is operating properly, the next steps are to check the operation of the local modem, the communications line and the remote modem.
Chapter 7 - Troubleshooting Procedures 3 Place your local MultiMux in normal operating mode by shutting power off and turning it back on. Make sure your 8-position DIP switch SW1 is in the off (closed) position. 4 With the two MultiMuxes in your network set properly, you can now enter data on the keyboard of each channel device and, if the network is operating correctly, the data will be correctly displayed on the channel device monitor.
Chapter 7 - Troubleshooting Procedures 7.7 MultiMux Functional Testing Procedures There are tests available on the MultiMux which check various functions within the MultiMux logic. These tests will assist you in trouble shooting problems which are not related to the composite communications channel or local channel devices.
Chapter 7 - Troubleshooting Procedures 5 To check the Watch-Dog circuitry, place the local MultiMux unit in Test Mode 9 (i.e., executing the Watch-Dog Timer Test) by entering the following command: AT&T9 (hit Return) The supervisory console will display the following message: Watch-Dog Timer Test #9 - wait for test indicator to turn off and when the test indicator comes back on, enter “AT” to end test.
Chapter 8- Service, Warranty, & Technical Support
Chapter 8 - Service, Warranty, & Technical Support 8.1 Introduction This chapter starts out with statements about your MultiMux 2-year warranty. The next section, Tech Support, should be read carefully if you have questions or problems with your MultiMux. It includes the technical support telephone numbers, space for recording your product information, and an explanation of how to send in your MultiMux should you require service. The final section explains how to use the Internet. 8.
Chapter 8 - Service, Warranty, & Technical Support 8.3 Repair Procedures for U.S. and Canadian Customers In the event that service is required, products may be shipped, freight prepaid, to our Mounds View, Minnesota factory: Multi-Tech Systems, Inc. 2205 Woodale Drive Mounds View, MN 55112 Attn: Repairs, Serial # ____________ A Returned Materials Authorization (RMA) is not required. Return shipping charges (surface) will be paid by MTS.
Chapter 7 - Troubleshooting Procedures 8.4 Repair Procedures for International Customers (Outside U.S.A. and Canada) Your original point of purchase Reseller may offer the quickest and most economical repair option for your Multi-Tech product. You may also contact any Multi-Tech sales office for information about the nearest distributor or other repair service for your Multi-Tech product. http://www.multitech.com/COMPANY/offices/DEFAULT.
Chapter 7 - Troubleshooting Procedures 8.5 Repair Procedures for International Distributors Procedures for International Distributors of Multi-Tech products are on the distributor web site. http://www.multitech.com/PARTNERS/login/ 8.6 Online Warranty Registration If you have access to the World Wide Web, you can register your Multi-Tech product online at http://www.multitech.com/register/.
Appendices
Appendix A - ASCII Character/Code/Hex/Decimal Conversion Chart Appendix A ASCII Character Code/Hex/Decimal Conversion Chart CTRL CODE HEX DEC @ A B C D E F G H I J K L M N O P Q R S T U V W X Y Z [ \ ] — NUL SOH STX ETX EOT ACK BEL BS HT VT ETB NUL SOH STX ETX EOT ENQ ACK BEL BS HT LF VT FF CR SO SI DLE DC1 DC2 DC3 DC4 NAK SYN ETB CAN EM SUB ESC FS GS RS US 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F 10 11 12 13 14 15 16 17 18 19 1A 1B 1C 1D 1E 1F CODE HEX 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 1
Appendix B - RS232C Interface Specifications Appendix B RS232C Interface Specification The MultiMux RS232C interface circuits have been designed to meet the electrical specifications given in the EIA (Electronic Industries Association) RS232C and CCITT (Consultative Committee of International Telegraph and Telephone) standards. All signals generated by the mux are approximately 10 volts when measured across a load of 300 ohms or greater.
Appendix B - RS232C Interface Specifications The computer or terminal should be supplied with a cable terminated with a Cinch DB25P (or equivalent) connector mounted in a Cinch DB51226-1 (or equivalent) hood assembly as specified by the RS232C/ V.24 standard.
Appendix C - Cabling Diagrams Appendix C Cabling Diagrams Channel Cables DCE to Channel cabling (with EIA pass Thru) PIN NO. To MultiMux Channel Connector PIN NO. 1 1 CHASSIS GROUND (AA) 2 2 TRANSMIT DATA (BA) 3 3 RECEIVE DATA (BB) 4 4 REQUEST TO SEND (CA) 5 5 CLEAR TO SEND (CB) 6 6 DATA SET READY (CC) 7 7 SIGNAL GROUND (AB) 8 8 CARRIER DETECT (CF) 20 20 DATA TERMINAL READY (CD) 22 22 RING INDICATOR (CE) 25 25 OUT OF SERVICE/BUSY To DCE Device (Communication Device i.e.
Appendix C - Cabling Diagrams Command Port Cables DCE to DTE cabling PIN NO. To MultiMux Command Port Connector PIN NO. 1 1 CHASSIS GROUND (AA) 2 2 TRANSMIT DATA (BA) 3 3 RECEIVE DATA (BB) 4 4 5 5 CLEAR TO SEND (CB) 6 6 DATA SET READY (CC) 7 7 SIGNAL GROUND (AB) 8 8 CARRIER DETECT (CF) 20 20 DATA TERMINAL READY (CD) 22 22 25 25 To DTE Device (Terminal Device i.e. ASCII Terminal) DCE to DCE cabling PIN NO. To MultiMux Command Port Connector PIN NO.
Appendix C - Cabling Diagrams Composite Link Cabling RS232C/V.24 *Configured Composite Link PIN NO. To External Synchronous Modem/DSU Connector PIN NO. 1 1 CHASSIS GROUND (AA) 2 2 TRANSMIT DATA (BA) 3 3 RECEIVE DATA (BB) 4 4 REQUEST TO SEND (CA) 5 5 CLEAR TO SEND (CB) 7 7 SIGNAL GROUND (AB) 8 8 CARRIER DETECT (CF) 15 15 TRANSMIT CLOCK (DB) 17 17 RECEIVE CLOCK (DD) 20 20 DATA TERMINAL READY (CD) 25 25 To MultiMux External Modem/DSU Connector V.
Appendix C - Cabling Diagrams RJ45 Cabling for Internal DSU Receive { Transmit { RT RR TT TR 1 2 3 4 5 6 7 8 Back to Back Mux Cable* 25-PIN CONNECTOR (FEMALE) FG TD RD RTS CTS SG DSR DCD TXC RXC DTR 1 2 3 4 5 7 6 8 15 17 20 INT. CLK 24 “DCE” 25-PIN CONNECTOR (FEMALE) 1 3 2 5 4 7 20 FG RD TD CTS RTS SG DTR 24 INT. CLK 6 8 15 17 DSR DCD TXC RXC “DTE” * This cable is used to connect two muxes back to back during testing.
Appendix D - Command Modem Commands Appendix D Command Modem Commands Command Description A Answer The Answer Mode forces the command modem into answer mode. Entering ATA when in the Command mode will immediately bring the command modem off-hook, out of the command mode and into the OnLine Answer mode, and cause it to retransmit its carrier signal over the phone line.
Appendix D - Command Modem Commands following it. For example, if you enter ATD5551212 and hit Return, the command modem will dial the number 555-1212. Valid dial characters are 0 through 9, A through D, # , and *. Dial modifiers are: , P R S=x T W ; @ and !. In pulse dialing, non- digit characters have no meaning. The Dial command can also be used in conjunction with a telephone set for manual dialing.
Appendix D - Command Modem Commands &F Load Command Modem Factory Defaults The Load Command Modem Factory Default &F Command resets the S-Registers and command modem commands to thefactory default values. They are as follows: S-Registers: S0=0, S1=0, S2=43, S3=13, S4=10, S5=8, S6=2, S7=30, S8=2, S9=6, S10=14,S11=95, S12=50, S18=0, S25=5, S26=1, and S28=0.
Appendix D - Command Modem Commands command. This “read” command enables the software to determine the type of modem with which it is communicating. When ATI or ATI0 (upper case) is entered, the command modem will respond with xxx, with the first two digits indicating model, and the third digit indicating the revision level. O Exiting Command Mode, Going Back On-Line You can bring the command modem out of command mode back into the On-Line Mode, by entering ATO (where O is the letter O, not the number 0).
Appendix D - Command Modem Commands for your dialing. An example of combining pulse and tone dialing could involve a PBX system where 9 had to be pulse-dialed first, then the rest of the number tone-dialed after pausing for a second dial tone. The number would be dialed by entering ATDP9,T5551212 and hitting Return. (The comma causes a pause, which is explained later in this appendix.
Appendix D - Command Modem Commands SN=xxx S-Register Read or Write The S command can be used to both assign a value to or read the current value of an S-Register. (Refer to Appendix G of this manual for the function of each S-Register.) The format for reading a register is to enter the letter S (upper case) followed by the register number and a question mark ? and then hit Return. For example, entering ATS7? and hitting Return will display the value of Register 7 in a 3 digit Decimal form.
Appendix D - Command Modem Commands Vo-1 Result Codes Word or Digit The command modem can display its Result Codes on your supervisory console. These codes can appear either in word(“verbose”) or single digit (“terse”) form. For example, if after dialing, no carrier signal is detected, the result can be displayed either as NO CARRIER or as the digit 3. The V command is used to determine which method is used.
Appendix D - Command Modem Commands You can also choose to completely eliminate the display of all of the Result Codes. This is accomplished by executing the Q command. &V View Active Configuration and User Profiles The View Active Configuration and User Profiles &V command displays the commands and S-Register settings along with the stored telephone numbers.
Appendix D - Command Modem Commands W Wait for Dial Tone The W command causes the command modem to wait up to a specified time for the dial tone to occur. The telephone number is dialed immediately upon dial tone detection. The S-Register S7 value determines the maximum wait time. If a busy signal is detected instead of dial tone, the command modem returns a BUSY result code and goes On-Hook, abandoning subsequent instructions on the command line.
Appendix D - Command Modem Commands dialing where actual dial tones are not detected, instead the command modem relies on timed pauses. The ATX0 enables the basic result codes while the ATX1 enables the extended result codes with call progress disabled on both commands. The ATX2 through ATX4 commands determine whether or not call progress is activated and extended result codes are enabled on each of these commands. The ATX2 command waits for a dial tone before dialing.
Appendix D - Command Modem Commands ATX3 Blind dialing is enabled along with extended result codes. Busy result code is enabled if the busy signal is detected. ATX4 Smart dialing is enabled with extended result codes. Smart dialing provides dial tone and busy signal detection. ATX4 is the factory default setting. &Y0-1 Select Stored Profile on Power UP The Select Stored Profile on Power Up (&Y) command determines which stored profile is established on power up or reset of the command modem.
Appendix D - Command Modem Commands specified by the number preceding the delimiter.The following characters are allowed to be stored: 0 through 9, A through D, T P R W # * , ! ; along with the delimiter (=). 0 to 9, A to D, # and * Dial Digits/Characters Digits 0 through 9 and characters A through D, # and * are valid dial characters. Characters A through D, # and * represent specific tone pairs and therefore, can be used only when tone dialing.
Appendix D - Command Modem Commands length of the pause of the comma, from two seconds to any other value from 0 up to 255 seconds. This is accomplished by accessing S-Register S8 which we explain in the Command Modem Commands Section. Each comma used in a dialing command does count as one of the forty allowed characters.
Appendix E - Command Modem S-Register Functions Appendix E Command Modem S-Register Function S0 Number of Rings Until Modem Answers Unit: 1 ring Range: 0-255 Default: 1 Description: SO defines how many rings the command modem will wait before answering an incoming call. Default value is zero rings (Decimal 0), which means the Auto-Answer feature is enabled. The maximum number of rings that can be configures is 255.
Appendix E - Command Modem S-Register Functions S3 Return Character Unit: Range: Default: Description: ASCII Character 0-127 13 Defines the character recognized as Carriage Return (RETURN) or “Enter”. Default setting is CTRL-M (Decimal 13), which is the aSCII code for the Return key on most key boards. May be set for any ASCII character. S4 Line Feed Character Unit: ASCII Character Range: 0-127 Default: 10 Description: Defines the character recognized as LINE FEED.
Appendix E - Command Modem S-Register Functions the telephone line. the minimum time is two seconds (Decimal 2) and is the factory default setting. Values greater than 2 seconds may be necessary if trouble is encountered getting dial tones. S7 Time for Carrier (Abort Timer) Unit: 1 second Range: 1-255, Default: 30 Description: Defines the Abort Timer (lack of carrier) delay time. Default value is thirty seconds (Decimal 2).
Appendix E - Command Modem S-Register Functions S10 Carrier Loss Disconnect Delay Time Unit: 100 mSec. Range: 1-255 Default: 7 Description: Sets the time a carrier signal must be lost before the modem disconnects. The S10 default setting is 1.4 seconds or 14 units (Decimal 14) where each unit is 0.1 second. Maximum delay is 25.4 seconds (Decimal 254). Setting the S10 value at 255 causes the command momdem to not disconnect at all with loss of carrier.
Appendix E - Command Modem S-Register Functions S19Not Used S20Not Used S21Reserved S22Reserved S23Reserved S24 Sleep Mode Inactivity Timer Unit: Sec. Range: 0-255 Default: 0 Description: S24 is used to set the amount of time the modem may be inactive before it will enter the sleep mode. The range of S24 is 0 to 255. The Sleep Mode Inactivity Time is automotically set to 5 seconds and Sleep Mode is inhibited when S24 = 255. S25 Detect DTR Change Unit: 0.
Appendix F - Flow Control Background Appendix F Flow Control Background Flow control refers to the techniques used by computer devices and multiplexers to stop and restart the flow of data from each other. Flow control is necessary so that a channel device does not receive more data than it can handle or vice versa (the MultiMux receives more data than its buffers can accommodate). Flow control by the mux to control data flow from a channel device is called Mux Initiated Flow Control.
Appendix F - Flow Control Background minicomputer so that the mux’s buffer capacity is not exceeded. We chose Xon/Xoff flow control for this example and are setting pace ON for all channel devices. NODE 1 MiniComputer NODE 2 Channel Channel 1 2 3 4 5 6 7 8 Link Mux Mux 1 2 3 4 5 6 7 8 PC PC PC PC PC PC PC Printer MiniComputer Flow Control In the example below, the flow control on the minicomputer works as follows: MiniComputer Channel 1 2 3 4 5 6 7 8 Data A. Flow Control B. C.
Appendix D - Command Modem Commands so the mux sends a start data Flow Control (ON) signal to the mini. D. Data from the mini again flows through the channel. Printer pacing and Flow Control The example below shows how Pacing and Flow Control work on a printer. (Host) MiniComputer Channel Link MUX 1 MUX Channel 1 Print Data Pace off Printer Prints Data Print Buffer Full Pace on Printer Ready A. B. Flow Control C. D. Flow Control off off E. F. G. H.
Appendix G - MMH2834 S-Registers Appendix G MMH2834 S-Registers Introduction This section covers the MMH2834 memory (option) registers called SRegisters, where certain MMH2834 modem and command mode configurations are stored. Each S-Register is assigned a number (S0, S1, S2, etc.). Use the S command to read and/or change the value stored in an S-Register (ATSr? to read and ATSr= to change S-Register values).
Appendix G - MMH2834 S-Registers S8 Pause Time for Comma Unit: 1 second Range: 0-255, 4-255**, 4-7*** Default: 2, 4**, 4*** Description: S8 sets the length of the pause caused by a comma inserted in a dialing command. The default setting is two seconds, (or two units Decimal 2) or four seconds, where each unit is one second. S8 may be set for up to 255 seconds. S8 also sets the time the modem waits before retrying a call after detecting a busy signal.
Appendix G - MMH2834 S-Registers S13 Remote Configuration Escape Character Unit: ASCII Character Range: 0-127 Default: 37 (%) Description: S13 defines the remote configuration escape character (which becomes your modem’s remote configuration character). The default is three percent symbols (%%%). When the S13 character is entered three consecutive times from a remotely connected site, your modem responds with its Remote Configuration procedure.
Appendix H - Dial Back-up Appendix H Dial Back-up The dialing associated with the MMH2834, when in leased line with dialback mode, involves placing a call from the originating MMH2834 due to a leased line failure. After a preset period of time, determined by S-Register S18 (refer to Appendix I for a description of the S-Registers), the MMH2834 automatically tries to restore the leased line.
Appendix I - Testing Your MMH 2834 Appendix I Testing Your MMH2834 I.1 Introduction Each time power is applied to a MultiMux with an internal MMH2834 modem, the MMH2834 performs an automatic self- test to ensure proper operation. The MMH2834 also has three diagnostic test features: Local Analog Loopback, Digital Loopback (remote/automatic) and Digital Loopback (local/manual). These diagnostic tests can be run after the modem is selected using the #CLA1 command.
Appendix I - Testing Your MMH 2834 I.2 Local Analog Loopback Test/V.54 Loop 3 In this test, data from your computer or terminal is sent to your modem's transmitter, converted into analog form, looped back to the receiver, converted into digital form and then received back at your monitor for verification. No connection to the phone line is required. See Figure I-1. Computer or Terminal Local MultiModem UUUUU UUUUU Digital Analog Type ATU0 or ATU1; hit ENTER Figure I-1.
Appendix I - Testing Your MMH 2834 I.3 Digital Loopback Test/V.54 Loop 2 (Loc/Man) In this test, your modem must be On-Line with another modem that can respond to a request for Digital Loopback, such as another MMH2834. The Digital Loopback Test is an on-line test that loops data sent from one modem across the phone line to another modem, then back to the first modem. See Figure I-2. There are two ways to put a modem into Digital Loopback mode. 1. Locally or Manually, described here in section I.3. 2.
Appendix I - Testing Your MMH 2834 maintaining the pseudo On-line mode with the remote modem. 4. Type ATU3 from the local PC and hit ENTER. Once you receive an OK message from your modem (if responses are enabled), the local modem is placed in Digital Loopback mode. 5. Data is typed from the remote keyboard. For this test, typing multiple upper case "U" characters is a good way to send an alternating test pattern of ones and zeros.
Appendix I - Testing Your MMH 2834 I.4 Digital Loopback Test/V.54 Loop (Rem/Auto) In this test, your modem must be On-line with another modem set up to respond to a request for Digital Loopback, such as another MMH2834. With the MMH2834, this ability to respond is controlled by the &T command. AT&T4 enables the response to Digital Loopback Test (remote/automatic). AT&T5 disables the response.
Appendix I - Testing Your MMH 2834 4. Type ATU2 and hit ENTER. The local modem responds to this command by transmitting an unscrambled marking signal, which causes the remote modem to place itself in Digital Loopback mode. Then the local modem exits Command mode and enters pseudo Online mode. 5. Type data from your keyboard. For this test, typing multiple upper case "U" characters is a good way to send an alternating test pattern of ones and zeros.
Appendix I - Testing Your MMH 2834 I.5 Synchronous Mode Testing The following tests must be run with your modem in Synchronous mode. The test procedures for Synchronous mode are different from those for Asynchronous mode. In Synchronous mode, you cannot access the modem’s AT commands. There is also a Local Analog Loopback Test, documented in section I.6.
Appendix G - MMH2834 S-Registers I.6 Local Analog Loopback Test (Sync Mode) This test diagnoses the connection between your MMH2834 and your computer or terminal. In Local Analog Loopback Test mode, data entered at the local computer or terminal are sent through the local modem’s transmit and receive circuits (much like entering an ATU or ATU1 command in Asynchronous mode). You then compare the test characters (multiple upper case “U” characters in Figure I-4) on your monitor with the characters you typed.
Appendix I - Testing Your MMH 2834 I.7 Digital Loopback Test (Loc/Man) Sync Mode This test must be run when you have a data connection with another modem. If a Local Analog Loopback Test resulted in errors, and this test passes without errors, then the problem exists in your computer-tomodem connection.
Appendix I - Testing Your MMH 2834 I.8 Digital Loopback Test (Rem/Auto)(Sync Mode) This test must be run when you have a data connection with another modem. In this test, data is passed to the remote modem and is looped back to the local modem (as if an ATU2 command was issued in Asynchronous test mode), as shown in Figure I-6. This lets you test the local and remote modem’s transmit and receive circuits, as well as your computer’s serial COM port and the phone lines.
Appendix J - Internal MMH2834 Composite Link Modem Commands Appendix J - Internal MMH2834 Composite Link Modem Commands J.1 Introduction Before the internal MMH2834 composite link modem commands can be entered, access to the modem has to be activated using the composite link access (#CLA1) command. When the MMH2834 modem is configured, the composite link access (#CLA0) command disables access from the command port to the composite link. The following sections describe the MMH2834 modem commands. Table J-1.
Appendix J - Internal MMH2834 Composite Link Modem Commands MMH2834 Modem Q Result Codes Enable/Disable Response Result Code Selection Echo Command Characters Result Code Terse/Verbose Result Code...Basic/Extended/Call Progress Configure Command Responses (Section J.1.5) &Q E V X MMH2834 Modem &T Condition Phone Line (Section J.1.
Appendix J - Internal MMH2834 Composite Link Modem Commands MMH2834 Modem Sr? Read and Assign S-Register Sr= Read Current S-Register Value Assign S-Register Value Values (Appendix G) MMH2834 Remote Configuration & Callback Security #CBN #DB #I #RCBNxx Passwords for Callback Phone Numbers Callback Security Enable/Disable Change LOGIN Password Erase Password Linked with Memory Location xx #S Change SETUP Password MMH2834 Modem U Self-Test Modem Test &T Enable/Disable Digital Loopback Signal
Appendix J - Internal MMH2834 Composite Link Modem Commands J.1.1 Dialing Action Commands Dial Command D The letter D in a command causes the MMH2834 to dial the telephone number immediately following it. For example, if you enter ATD5551212 and hit RETURN, the MMH2834 dials the number 555-1212. The MMH2834 gives you several choices of dialing methods. You can use tone or pulse dialing, by inserting a letter T or a P in the command string. (See section J.1.
Appendix J - Internal MMH2834 Composite Link Modem Commands RETURN. Do not include the letter D in this command, or the stored number will be erased (also see Section J.1.3., on Phone Number Memory Commands). DTR Dialing $D An alternate method of causing the MMH2834 to automatically dial is DTR Dialing. Data Terminal Ready (DTR) is a signal that comes into the modem from the terminal or computer to which it is connected, on pin 20 of the RS232C interface.
Appendix J - Internal MMH2834 Composite Link Modem Commands J.1.2 Dial Modifier Commands Pulse or Tone Dial P T The MMH2834 dials numbers using either pulse or tone dialing, or a combination of both methods. Pulse dialing is a method used by rotary-dial telephones, which involves the timed opening and closing of line relay. Tone dialing is the method used by pushbutton (touch tone) telephones, and is sometimes referred to as DTMF, or DualTone Multi-Frequency dialing.
Appendix J - Internal MMH2834 Composite Link Modem Commands Long Space Disconnect Y When two modems are connected in Normal mode (i.e. withouterror correction) there is no "polite" means of requesting a disconnect. A link disconnect request packet is sent under reliable connections. As a result some "garbage" may be received when a hangup command is issued.
Appendix I - Testing Your MMH 2834 message. Hitting any key also aborts the $ command. The following is an example of this command: ATDT1028806127853500 $123456789 (access/phone number) (credit card number) Quiet Answer @ The @ command causes the MMH2834 to wait before processing the next symbol in the dialing string. The wait is for one or more ringbacks followed by 5 seconds of silence. If 45 seconds pass before the rings and silence, a NO ANSWER (R) result code is processed.
Appendix J - Internal MMH2834 Composite Link Modem Commands J.1.3 Phone Number Memory Commands Storing Phone Numbers D...N A telephone number and command line of up to sixty characters may be stored in the MMH2834’s number memory. As many as ten of these numbers may be stored. Each number will be given a name, using the codes N0, N1, N2 up to N9.
Appendix J - Internal MMH2834 Composite Link Modem Commands L shown below. All digits and command letters will be shown. The number’s “name” (0 thru 9) is shown first, followed by the complete dialing command and telephone number as originally entered. Simply enter ATL and hit RETURN to display these numbers on your video screen or printer.
Appendix J - Internal MMH2834 Composite Link Modem Commands J.1.4 Configuration and Default Storage Commands Store Configuration & S-Register Parameters in Non-Volatile Memory &W The MMH2834 can store configuration parameters and S-Register values in its non-volatile read/write Random Access Memory (RAM) memory. The &W command does this which prevents any reconfiguration from being lost on a power-down or Reset (ATZ) condition.
Appendix J - Internal MMH2834 Composite Link Modem Commands Async/Sync Mode Switching &M This command can be used to set the on-line mode to either synchronous or asynchronous. AT&M0 will set the MMN2834 to Asynchronous mode, and all communications will be Asynchronous, in both On-line and Command modes. AT&M1 causes the MMH2834 to communicate asynchronously when in Command mode and switch to synchronous mode while on-line. The modem defaults to &M0 (asynchronous communications) on reset or power-up.
Appendix J - Internal MMH2834 Composite Link Modem Commands J.1.5 Command Response (Result Code) Commands Echo Command Mode Characters E If the MMH2834 is connected to a full-duplex computer, it may be necessary for the modem to be configured to echo back characters entered while in the command mode in order for them to be displayed. The E command is used to configure the Command Mode echo, with ATE0 disabling the echo and ATE1 enabling the echo (default).
Appendix J - Internal MMH2834 Composite Link Modem Commands 12 13 19 21 24 26 28 CONNECT 9600 CONNECT 14400 CONNECT 19200 CONNECT 21600 CONNECT 24000 CONNECT 26400 CONNECT 28800 AT&Q0 selects Multi-Tech responses with Reliable/ Compression modifiers. With this command, the terse result code for CONNECT 2400 is 9.
Appendix J - Internal MMH2834 Composite Link Modem Commands Call Progress Selection X combinations related to these methods. You can choose to have certain responses suppressed, or whether or not you want speed indications along with the CONNECT responses. You can also pick and choose certain responses in order to match up with “Standard AT” responses. (Refer to Appendix F for a summary of Result Codes.) The MMH2834 provides “Basic” and “Extended” Result Code sets.
Appendix J - Internal MMH2834 Composite Link Modem Commands Five different X commands are available (X0 through X4), with five different effects on the MMH2834’s Result Codes. X0 X1 Provides the basic (short) result codes and provides “dumb” dial capabilities. Provides the extended result codes and provides “dumb” dial capabilities. The remaining X commands affect Call Progress, and turn on Extended Result Codes. X2 X3 X4 Looks for dial tone only and will not provide a busy response.
Appendix J - Internal MMH2834 Composite Link Modem Commands J.1.6 Phone Line Conditioning Commands Enable or Disable Recognition of Remote Digital Loop Signal &T The MMH2834 has several self-test features (covered in Appendix J). The tests are activated with different U commands, such as ATU1, and so forth. The &T command is a phone line conditioning command that enables or disables the modem's ability to recognize the Remote Digital Loop (RDL) test signal.
Appendix J - Internal MMH2834 Composite Link Modem Commands J.1.7 RS232C Interface Control Commands Data Terminal Ready Control &D Data Terminal Ready (DTR) on pin 20 of the RS232C interface is required in order for the MMH2834 to operate. A high DTR signal tells the modem that the device to which it is connected is active, or "ready" to communicate through the modem. DTR has some other MMH2834 functions. DTR can be used to trigger a dialing sequence, called DTR Dialing.
Appendix J - Internal MMH2834 Composite Link Modem Commands J.1.8 Error Correction Commands You can use AT commands to place your MMH2834 one of three V.42 (error correction) modes of operation. V.42 Mode Select #L #L0 Command #L1 Command #L2 Command #L3 Command Auto-Reliable Buffering $A The V.42 standard implements both MNP Class 3 & 4 and LAP-M error correction methods. The V.42 Mode Select command (#L) selects which type of error correction (MNP or LAP-M) your MMH2834 uses for transmissions.
Appendix J - Internal MMH2834 Composite Link Modem Commands Enable/Disable Auto-Reliable Fallback Character $F Retransmit Count $R V.42 Error Correction/300bps $E In Auto-Reliable mode, the modem is given four seconds to establish a Reliable connection. If a single CARRIAGE RETURN is received from the remote modem during this four second period, the Auto-Reliable modem assumes that the remote modem is not in Reliable mode and drops to Normal mode.
Appendix J - Internal MMH2834 Composite Link Modem Commands J.1.9 Compression and Maximum Block Size Commands Data Compression Maximum Block Size &BS The data compression (&E14) command enables data compression. The maximum size of Reliable mode data blocks can be controlled with the &BS command. MNP 3 sends blocks of 1 to 64 characters. MNP 4 and 5 typically send blocks of 1 to 256 characters and LAP-M typically sends 128 characters.
Appendix J - Internal MMH2834 Composite Link Modem Commands J.1.10 Speed Conversion Commands Speed conversion is a necessary part of data compression since data must be presented to the modem faster than it can handle data, if data compression is to be effective. Speed conversion allows the MMH2834 to communicate at one speed over the phone line, and at another speed at the RS232C interface.
Appendix J - Internal MMH2834 Composite Link Modem Commands Serial Port Baud Rate $SB The $SB command presets the speed of the MMH2834's serial (RS232C) port, in both Originate and Answer modes. Speed conversion allows you to set this serial port baud rate at a fixed speed of up to 115,200 bps, regardless of the modem’s transmission speed setting. In order for this command to be effective, the modem’s Speed Conversion feature must first be turned off with the $BA command.
Appendix J - Internal MMH2834 Composite Link Modem Commands J.1.11 Immediate Action Commands Help Screens $H The Help command is designed to give you short explanations on how to use each MMH2834 command. The Help command can be quite useful if your manual is not handy and you are in the middle of a communications session. Although the explanations are quite abbreviated compared to those in this manual, they will be helpful reminders when needed.
Appendix J - Internal MMH2834 Composite Link Modem Commands current on-line condition (e.g., Link Type, Line Speed, Serial Speed, Type of Error Correction/Data Compression, Number of past Retrains,etc.). An example of L8 listing is shown below: ATL8 ****** ONLINE DIAGNOSTICS LINK TYPE LINE SPEED SERIAL SPEED ERROR CNTRL/COMPRESS FALL BACK/FORWARD LINE TYPE DATA FORMAT LINE QUALITY RECV. SIGNAL LEVEL TRANS SIGNAL LEVEL NUMBER OF RETRAINS ROUND TRIP DELAY ****** V.
Glossary
Glossary A AC (Alternating Current): A power source whose signal crosses a reference voltage (usually called ground or zero). Alternating between a maximum and minimum voltage, AC may also be referred to as a bipolar signal. Contrast with DC. ACK (ACKnowledgement code) (pronounced "ack"): A communications code sent from a receiving modem to a transmitting modem to indicate that it is ready to accept data. It is also used to acknowledge the errorfree receipt of transmitted data. Contrast with NAK.
Glossary B C Baud: Baud is rate, the signalling rate of a line, the switching speed, or the number of transitions (voltage or frequency changes) that are made per second. Transmission speeds are often expressed in baud, though bits per second is more accurate. The speed at which your computer talks to your modem. Capacitor: An electronic device that stores an electrical charge. It comes in varying sizes for use in anything from power supplies to the tiny cells in dynamic RAM chips.
Glossary Circuit switching: The temporary connection of two or more communications channels using a fixed, non-shareable path through the network. Users have full use of the circuit until the connection is terminated. Decibel (dB): A unit of measurement for signal strength based on logarithmic increments. A decibel is a relative measurement that is derived from an initial reference level and a final observed level.
Glossary DTMF (Dual-Tone MultiFrequency): A generic push-button concept made popular by AT&T TouchTone. Decibel (dB): A unit of measurement for signal strength based on logarithmic increments. A decibel is a relative measurement that is derived from an initial reference level and a final observed level. Default: This is preset value or option in software packages, or in hardware configuration, that is used unless you specify otherwise.
Glossary of a graphical document and, therefore, cannot be accurately interpreted according to any character code. Firmware: A category of memory chips that hold their content without electrical power, they include ROM, PROM, EPROM and EEPROM technologies. Firmware becomes "hard software" when holding program code. Flash Memory: A memory chip that holds its content without power, but must be erased in bulk. The term comes from its ability to be erased "in a flash".
Glossary Mid-range computer: A term coined by IBM referring to any of their Advanced Business Systems computers. This product line was originally called their mini-computers, but as the number of supported users approached mainframe capabilities, the term "mid-range" caught on. Mnemonics: A term assigned to a complex idea, value, or list of information which is found to be representative of that information. Computer commands are almost entirely mnemonics. Mnemonics are used as memory aids for people.
Glossary Phase: The timing of a signal based upon the starting point of each cycle in another signal. To be detected phase requires the comparing of two signals. If the cycle of two signals begin at the same point, they are said to be "in-phase". In-phase signals add, while out-of-phase signals tend to cancel each other. Port: A location for input or output data exchange. Computers, muxes, etc. have ports for various purposes. Program: A collection of computer instructions that tell the computer what to do.
Glossary a conversion chip called a "UART" which translates between internal parallel and external serial formats. Switched Line: In communications, a physical channel established by dynamically connecting one or more discreet segments. This connection lasts for the duration of the call after which each segment may be used as part of a different channel. Contrast with leased line.
Glossary X Y Z 193
Index Index Baud Rate Select (Bxxxxx) Command, 65 C Symbols &T command, 154 14.4, 9.6, 48, 24 Composite Link Speed Indicators, 37 56, 19.
Index Command Port Cables, 122 COMMAND PORT Connector, 15, 40 Command Summary, 53, 54, 55, 56, 57 Communications, 13 Composite Link, 13, 20 Composite Link Access Command (#CLA), 79 Composite Link Cabling, 47 COMPOSITE LINK DIGITAL DSU Connector, 15 COMPOSITE LINK EXTERNAL RS232C/V.
Index esult Codes (Basic Extended) and Call Progress (, 173 Extended Result Codes, 175 EXTERNAL COMPOSITE LINK RS232C/V.
Index Local Modem and Communications Line Testing, 108 Long Space Disconnect (Y), 166 M Maximum Speed, 24 Memory Test Command (&T1T2), 87 MiniComputer Flow Control, 144 Modem Baud Rate ($MB), 181 Modem Configuration Select Command ($MC), 81 Modem Reset (Z), 170 "Multi-Tech"/"Standard AT" Result Codes (&Q), 172 MultiMux Functional Testing Procedures, 110 MultiMux Operating Procedures, 91 Mux Clock Command ($MUXCL), 78 Mux Speed Command ($MUXSP), 78 P Pacing Control Command (F5F6), 67 Parameter Memory, 19 P
Index Response Time Control, 17 Response Time Priority Command (R0-R3), 70 Result Codes Enable/Disable and No Response (Q), 172 Retransmit Count ($R), 179 Return Character, 139 S3, 139 Return to Command Mode After Dial Execution (;), 166 Ringer Equivalence Number (REN), 21 Rings Which Have Occurred S1, 138 RJ45 Cabling for Internal DSU, 124 RS232C Interface Control Commands, 177 RS232C Interface Specification, 119 S S-Registers, 146 Select Downline Load Parameters Command (&SR), 72 Select Local Parameters
Index Universal Channel Parameters (C0) Command, 65 Unpacking, 46 V V.
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