AUGUST 1998 PCW22A-R3 PCW22C-R4 Protocol Converter A/S-2G G A/S-2 TXD CUSTOMER SUPPORT INFORMATION RXD RTS A PORT DTR CTS DSR CDA CDB TXD RXD RTS CTS B PORT DSR DTR TXC RXC PWR Order toll-free in the U.S.: Call 877-877-BBOX (outside U.S. call 724-746-5500) FREE technical support 24 hours a day, 7 days a week: Call 724-746-5500 or fax 724-746-0746 Mailing address: Black Box Corporation, 1000 Park Drive, Lawrence, PA 15055-1018 Web site: www.blackbox.com • E-mail: info@blackbox.
FCC STATEMENT FEDERAL COMMUNICATIONS COMMISSION AND INDUSTRY CANADA RADIO FREQUENCY INTERFERENCE STATEMENTS This equipment generates, uses, and can radiate radio frequency energy and if not installed and used properly, that is, in strict accordance with the manufacturer’s instructions, may cause interference to radio communication.
PROTOCOL CONVERTER A/S-2G INSTRUCCIONES DE SEGURIDAD (Normas Oficiales Mexicanas Electrical Safety Statement) 1. Todas las instrucciones de seguridad y operación deberán ser leídas antes de que el aparato eléctrico sea operado. 2. Las instrucciones de seguridad y operación deberán ser guardadas para referencia futura. 3. Todas las advertencias en el aparato eléctrico y en sus instrucciones de operación deben ser respetadas. 4. Todas las instrucciones de operación y uso deben ser seguidas. 5.
TABLE OF CONTENTS Table of Contents 1.0 Specifications .......................................................................................................................................5 2.0 Introduction.........................................................................................................................................6 3.0 Installation ...........................................................................................................................................
PROTOCOL CONVERTER A/S-2G 4.2 5.0 4 Synchronous Device to Asynchronous Device........................................................................22 4.2.1 Line Control ...............................................................................................................22 4.2.2 Synchronous Input Data Format...............................................................................22 4.2.3 Data Conversion .....................................................................................
CHAPTER 1: Specifications 1.0 Specifications Protocol — Asynchronous: TTY (ASCII) Bisynchronous: 2770, 2780, 3741, and 3780 (EBCDIC) Ports — A: Asynchronous B: Synchronous/bisynchronous Speed — Up to 19.
PROTOCOL CONVERTER A/S-2G 2.0 Introduction The Model A/S-2G provides compatibility between an asynchronous, ASCII coded device and a synchronous, EBCDIC coded device. It is desirable, prior to installation, to review the following checklist to ensure the appropriateness of all the devices in the system for the planned application.
CHAPTER 3: Installation 3.0 Installation 3.1 UNPACKING AND INSPECTION After unpacking the A/S-2G, inspect it for shipping damage. Should there be any noticeable damage, save the cartons and contact the carrier who delivered the box to place a freight damage claim. To open the A/S-2G, take out the four screws from the bottom. Lift off the cover. With the cover removed, visually inspect for components that may have been loosened in shipment.
PROTOCOL CONVERTER A/S-2G Block size for the 2770/2780 is normally limited to 160, but block size is 400 if the 2770/2780 has the Multiple Record Transmission. Block size for the 3780 is 512. Switch #4 ON = sends CR LF (Carriage Return, Line Feed) to asynchronous device immediately after each logical end of block character (ETB, or ETX) is received from the synchronous side. OFF = Normal operation Switch #5 ON = Variable-length blocks.
CHAPTER 3: Installation Switch #4 ON = Self-Diagnostics Mode. OFF = Normal Operation. Switch #5, #6—Block Size Specification. 5 6 OFF OFF 80 Characters OFF ON 128 Characters ON OFF 256 Characters ON ON 512 Characters NOTE For 3741, set SW3, Switch #5: OFF (Fixed length)SW2, Switch #5: OFF, and Switch #6: OFF (128 character block) Switch #7, #8—Asynchronous Parity Specification.
PROTOCOL CONVERTER A/S-2G NOTE Self-diagnostics will normally display the switches as they are set on the printed circuit board. If the switches were reconfigured (see Section 3.2.4), the switches will be displayed as they are set in the software. 3.2.4 RECONFIGURE SWITCH MODE To enter the Reconfigure Switch Mode, a terminal must be connected to Port A. When you type an ampersand (“&”) and then a pound sign (“#”), the A/S-2G will enter the Self-Diagnostics/Reconfigure Switch menu.
CHAPTER 3: Installation If SW3, Switch #7 is ON, the A/S-2G will drop DTR when only 32 character spaces remain in the buffer. The A/S-2G will reassert DTR as soon as there are at least 33 character spaces available. For most applications, it is best to configure SW3, Switch #7 ON. If SW3, Switch #7 is OFF, the A/S-2G does not use DTR to control the buffer. Instead, the A/S-2G will issue either an X-ON or X-OFF to control data flow. 3.3.
PROTOCOL CONVERTER A/S-2G 3.3.5 CARRIER OPTIONS If the carrier detect signal is to be driven by the A/S-2G configuration (DCE), the jumper labeled CAR A ENB must be installed. CAR A ENB is located below U20. Refer to the printed circuit board, Figure 5-2, on page 28. The carrier control jumper, CARR A, in between U18 and U19 on the circuit board (See Figure 5-2 on page 28) should be set as follows: (a) continuous carrier—place the jumper over the ON position.
CHAPTER 3: Installation there is data to be transmitted. Once the A/S-2G receives CTS from the attached device, it will transmit the data. When the synchronous port (Port B) is configured as DTE, the CTS B jumper must be placed over the CNT position. Place the CTS B jumper over the CNT position when Port B is configured as DCE. 3.4.3 BAUD RATE OPTIONS For externally provided synchronous clocking, the baud rate for the synchronous communication line is determined by the modem or modem eliminator.
PROTOCOL CONVERTER A/S-2G 3.4.8 COMMAND PASS-THRU To use the command pass-thru feature, the command must be preceded by &% and terminated by &%. Example: &%-Command-&% Commands consist of character pairs. Each pair must represent a valid Hexidecimal value (i.e. zero through 9 or A through F). Example: To send an escape sequence to an attached ASCII device, such as “ESC A,” the following EBCDIC string must be sent to the A/S-2G: &%lB41&%.
CHAPTER 4: Operation 4.0 Operation By its nature, a protocol converter must operate differently in each direction, since it is communicating with separate devices. Therefore, its operation will be discussed separately for asynchronous to synchronous operation and for synchronous to asynchronous. 4.1 ASYNCHRONOUS DEVICE TO SYNCHRONOUS DEVICE 4.1.1 LINE CONTROL When the A/S-2G is initially connected to an AC power source or reset, the asynchronous device can transmit data.
PROTOCOL CONVERTER A/S-2G ASCII CHARACTERS NOT TRANSLATED TO EBCDIC CR (Carriage Return) when SW3, Switch #3 is ON, LF (Line Feed), Control characters are not passed. Character NUL SOH STX ETX EOT ENQ Hex 00 01 02 03 04 05 Character ACK DLE NAK SYN ETB US Hex 06 10 15 16 17 1F Table 4-2. ASCII characters not translated to EBCDIC. In 3741 protocol, each block contains only one record. If SW3, Switch #5 is OFF, the A/S-2G will fill the block with spaces until it reaches 128 characters .
CHAPTER 4: Operation If SW3, Switch #7 is OFF, the A/S-2G will send an X-OFF (ASCII DC3, 13 Hex) to the asynchronous device when RAM reaches a nearly-full state. This prevents data from being lost due to a buffer overrun. When RAM space is available, the A/S-2G will send an X-ON (ASCII DC1, 11 Hex) to resume transmission. Alternatively, if SW3, Switch #7 is ON, the A/S-2G will lower the DTR (Pin 20) when RAM reaches a nearly-full state.
PROTOCOL CONVERTER A/S-2G Data Flow — A/S-2G to Synchronous Device Bisynchronous Device A/S-2G Converter Asynchronous Device IF 2270 - 2780 AA AA 32 32 32 32 02 (text up to 80 characters), IF, BCC1, BCC2; etc.
CHAPTER 4: Operation Data Flow — A/S-2G to Synchronous Device Bisynchronous Device A/S-2G Converter Asynchronous Device If A/S-2G buffer is nearly full when asynchronous device is transmitting: X-OFF Holds up transmission while buffer clears DC3 (ASCII 13 Hex) or drop DTR CTS or user-specified lead Send block C Frees up buffer space.
PROTOCOL CONVERTER A/S-2G Data Flow — A/S-2G to Synchronous Device Bisynchronous Device A/S-2G Converter Asynchronous Device (Echo CR LF) Send block F (Echo all but CR LF) ENQ 2-second interval WAK WAK resets ENQ counter ENQ Sync device buffer space available ACK 1 Send block F ACK 0 (Echo CR LF) If data not yet available from asynchronous device: If over 3-second interval AA 32 32 32 32 02 2D FF FF TTD NAK AA AA 32 32 32 32 3D FF FF Line release or turnaround: Send block G, (end with EOT Hex 04) (Ech
CHAPTER 4: Operation Data Flow — A/S-2G to Synchronous Device Bisynchronous Device A/S-2G Converter Asynchronous Device IF 2270 - 2780 AA AA 32 32 32 32 02 (text up to 80 characters), IF, BCC1, BCC2; etc.
PROTOCOL CONVERTER A/S-2G 4.2 SYNCHRONOUS DEVICE TO ASYNCHRONOUS DEVICE 4.2.1 LINE CONTROL When the A/S-2G is initially connected to an AC power source or reset, the synchronous device can gain control of the line by sending an ENQ. When the asynchronous side has control of the line, a turnaround cannot occur until an “End of Transmission” character has been entered from the controlling device. This character will be a “Control D” (ASCII 04 Hex) on the asynchronous side. 4.2.
CHAPTER 4: Operation Should the A/S-2G receive a DLE EOT (disconnect), the A/S-2G will cycle the synchro-nous DTR lead off for 2 seconds. This action will disconnect a phone line if the DTR B jumper is set for CNT. NOTE The A/S-2G will cycle the synchronous DTR lead off for 2 seconds whether the DLE EOT sequence comes from the synchronous or asynchronous side.
PROTOCOL CONVERTER A/S-2G Data Flow — A/S-2G to Asynchronous Device Bisynchronous Device A/S-2G Converter Asynchronous Device ENQ ACK 0 Send data block A ACK 1 Send block A Unformatted mode— successive characters (including spaces) appear one after another as sent If A/S-2G buffer is nearly full when synchronous device is transmitting: Send data block B 2-second interval WAK ENQ 2-second interval WAK Send block B ENQ WAK resets ENQ counter with respect to ENQ time out ACK 0 (when buffer available) Se
CHAPTER 4: Operation Data Flow — A/S-2G to Asynchronous Device Bisynchronous Device A/S-2G Converter Asynchronous Device Send data block D NAK Send data block D ACK 0 when available Send block D If data not properly received by A/S-2G: Send data block E NAK Retransmit block E ACK 1 (when correctly received) Send block E If data not yet available from synchronous device while synchronous line to A/S-2G is engaged: 2-second interval from previous ACK TTD NAK 2-second interval TTD NAK Continues until data
PROTOCOL CONVERTER A/S-2G Data Flow — A/S-2G to Asynchronous Device Bisynchronous Device A/S-2G Converter Line release or turnaround Send data block F (last block) ACK 0 Send block F EOT Send C R LF EOT to asynchronous device if SW3, switch #2 is ON Line can now be turned around or A/S-2G in idle mode 26 Asynchronous Device
CHAPTER 5: Conversions and Connections 5.0 Conversions and Connections 5.1 TRANSPARENCY MODE OF OPERATION With a special transparency PROM installed, the A/S-2G will communicate with a host system in IBM binary synchronous transparent mode. To special-order the transparency PROM, please call technical support. In transparent mode, no character translations are performed in either direction, allowing transmission of binary file such as raw data or program object files.
PROTOCOL CONVERTER A/S-2G 5.
CHAPTER 5: Conversions and Connections 5.4 CODE CONVERSIONS The conversions used in the standard 2770, 2780, 3741, and 3780 PROMs are shown in the following charts. Your PROM can be customized. Please call Technical Support if you have particular translation requirements. Abbreviations: Dir.
PROTOCOL CONVERTER A/S-2G Character or ASCII Graphic Hex Dir.
PWR RXC B TXC B DSR B DTR B CTS B 6116 U8 28 1 U9 ON R1 6264 DSR A DSR B U7 EPROM RTS B RXD B TXD B CDB CDA A DSR A DTR A CTS A RTS A RXD A TXD A U12 SW3 U13 8 DETECT CDA 64 1 ON SW2 U17 8 DETECT CDB U16 CTS A 1 ON SW1 U21 CAR A ENB U20 U19 CD 8 U26 U25 U24 CNT U23 U22 EXT EXT B SME B DTR A CNT ON DTR B CTS CNT B ON CAR B ENB U18 ON CNT A CARR ON CNT CARR B CNT ON XTAL U30 DTE-B U29 DCE-B SME B U28 DTE-A U27 DCE-A PORT B DB25 DTR PO
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