MT56DSU2 Owner’s Manual MultiDSU56K Model MT56DSU2 Owner’s Manual 82017502 1
MT56DSU2 Owner’s Manual MultiDSU56K Model MT56DSU2 Owner’s Manual P/N 82017502 Rev. C 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 1993, by Multi-Tech Systems, Inc. Multi-Tech Systems, Inc. makes no representation or warranties with respect to the contents hereof and specifically disclaims any implied warranties of merchantability or fitness for any particular purpose.
MT56DSU2 Owner’s Manual Table of Contents CHAPTER 1-INTRODUCTION AND DESCRIPTION 1.1 1.2 1.3 1.4 1.5 1.6 1.7 Introduction About This Manual Description CSU/DSU Basics Features FCC Regulations for Telephone Line Interconnection Specifications CHAPTER 2- HARDWARE INSTALLATION 2.1 2.2 2.3 2.4 Introduction Default DIP Switch Settings Changing Default Settings Installation Procedure CHAPTER 3- OPERATION 3.1 Introduction 3.2 Options 3.2.1 Data Rate 3.2.2 Async/Sync 3.2.3 Anti-Streaming 3.2.
MT56DSU2 Owner’s Manual Chapter 1 - Introduction and Description 1.1 Introduction Congratulations! Your new MultiDSU56K is one of the finest DSU/CSUs available today. As a combined CSU (Channel Service Unit) and DSU (Data Service Unit), it provides a direct connection to the DATAPHONE® Digital Service (DDS) network.
MT56DSU2 Owner’s Manual MultiDSU56K SD RD CD 56 19.2 96 48 Send Rcv Carrier 56K 19.2K 9600 4800 CTS RTS NS DOS TM Multi-Rate DSU/CSU Clear Request NoSgnl Outage Test Figure 1-1. Multi-Tech System’s MultiDSU56K 1.4 CSU/DSU Basics A DSU (Data Service Unit) and a CSU (Channel Service Unit) are typically connected to provide the interface between DTE (data terminal equipment) and the DDS (Digital Data Service) or other four-wire network.
MT56DSU2 Owner’s Manual 1.5 Features The MultiDSU56K provides many useful features. Standard features include V.35 and RS232 connections and either synchronous or asynchronous transmission; synchronous at rates up to 56000 bps and asynchronous up to 19200 bps; selectable digital rates that match the services offered by the carriers. Other features include user-selectable clocking options, elastic store for analog off-net extensions, anti-streaming, and RTS and DSR signal forced on selection.
MT56DSU2 Owner’s Manual 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 in Appendix B.
MT56DSU2 Owner’s Manual 1.7 Specifications Model Number MT56DSU2 Device Operation combined DSU and CSU Data Rates Synchronous: Asynchronous: 2400, 4800, 9600, 19200, 56000 bps 2400, 4800, 9600, 19200 bps Interfaces RS232C V.35 DDS DB25S (female) 34-pos. rectangular (female) RJ48 8-position keyed jack Power Requirements 117V AC, 50-60 Hz, 10 Watts Temperature 0 to 50 degrees C Humidity 95% (non-condensing) Dimensions 1.38" H x 6.15" W x 9" D 3.5 cm H x 15.6 cm W x 22.9 cm D Weight 2 Lbs. (.
MT56DSU2 Owner’s Manual Delay Times (in secs.): 2400 4800 9600 19200 56000 82017502 RTS/CTS DCD on DCD off 8.1 7.5 7.0 4.3 2.6 3.5 2.2 1.6 1.5 1.0 0.8 0.7 0.4 0.3 0.
MT56DSU2 Owner’s Manual Chapter 2 – Hardware Installation 2.1 Introduction This chapter provides the information needed to configure and install the MultiDSU56K. This manual assumes the reader is familiar with the function and operation of data communications equipment and is technically qualified to provide installation service. Safety Warning Telecom 1. Never install telephone wiring during a lighting storm. 2.
MT56DSU2 Owner’s Manual The Mu11iDSU56K DIP switches are shown and described below. Figure 2-1 MuIttDSU56K Board Layout 2.2.1 12-Position DIP Switch (#1-12) The 12-position DIP switch is used to select the data rate, clocking, RTS control, DSR control, AsynclSync operation, diagnostic modes (Loopback Test, Test Pattern), Circuit Assurance, and System Status. The default settings are shown in Table 2-1. If you want to make changes to one of these settings, refer to section 2.3. 2.2.
MT56DSU2 Owner’s Manual An adhesive-backed label containing the DIP switch setting information is provided on the bottom of the MultiDSU56K; a sample label is shown below for reference.
MT56DSU2 Owner’s Manual The factory default settings are indicated by an * in table 2-1. Table 2-1. MuII1DSU56K Switch Settings Switch Description Data Rate (in bps) 2400 4800 1 Down Down 2 Down Up 3 Down Down Clocking Internal 4 Up 5 Up RTS Control 6 9600 19.
MT56DSU2 Owner’s Manual 2.4 Installation Procedure Installation of the MultiDSU56K includes making cable connections to the back panel and turning power on. The MultiDSU56K back panel is shown below. Figure 2-2. MultiDSU56K Back Panel Perform the steps below to install the MultiDSU56K. Table 2-2. Hardware Installation Procedure Perform the following procedure to install your MultiDSU56K. 1. Verify that the Dip switches on the MultiDSU56K are set for your particular configurations; refer to Table 2-1.
MT56DSU2 Owner’s Manual Chapter 3 – Operation 3.1 Introduction This chapter provides information on the operating functions of the MultiDSU56K. During normal operation the MultiDSU56K requires no operator intervention. Many of the optional features of the MultiDSU56K are selected by setting a DIP switch on the PC board. Please refer to Changing the Default DIP Switch Settings (Chapter 2) to change your particular environment. 3.
MT56DSU2 Owner’s Manual 3.2.4 Elastic Store This function allows the MultiDSU56K to compensate for small timing phase “drifts” that occur in applications using analog modems for off-net (non-DDS) extensions. An analog off-net extension application is described in Appendix A. This option should be enabled on all MultiDSU56Ks that are connected to analog modems. Notes for off-net (elastic store enabled) sites: • a special DCE-DCE cross-over cable is required (not supplied by Multi-Tech).
MT56DSU2 Owner’s Manual 3.2.8 RTS Forced On With this option enabled, the MultiDSU56K provides a continuous CTS signal, disregarding the state of the RTS signal at the DTE interface connector. This will provide a continuous outbound indication to the network and remote (far-end) device that there is a “Carrier on” condition. For many (e.g., point-to-point) networks, it is best to maintain a “carrier on” status on the communications channel to help minimize line turnaround delays.
MT56DSU2 Owner’s Manual The MultiDSU56K uses 4-wire non-loaded metallic circuits for LADS applications. The table below outlines approximations for the maximum cable length for limited distance applications. Data Rate 2400 bps 4800bps 9600 bps 19200bps 56000 bps 19AWG 22.0 19.0 15.0 11.9 10.0 Wire Gage 22AWG 24AWG 15.0 12.0 13.0 10.0 10.0 7.0 7.0 5.0 6.0 4.2 26AWG 9.5 8.0 5.5 4.0 3.
MT56DSU2 Owner’s Manual Chapter 4 - Troubleshooting 4.1 Introduction All of the indicators used in normal operation of the MultiDSU56K are on the front panel. Each front panel LED is labeled, as explained below. The LEDs provide status and maintenance information on the MultiDSU56K, as well as the attached network and line. There are no front panel switches on the MultiDSU56K; refer to Chapter 2 of this manual for option configuration DIP switch settings. 4.
MT56DSU2 Owner’s Manual 4.2.6 96 Indicator The 96 LED lights when the “Data Rate” selection is set at 9600 bps. This indicator will be off for all other data rates. Refer to Chapter 2 for switch settings. 4.2.7 48 Indicator The 48 LED lights when the “Data Rate” selection is set at 4800 bps. This indicator will be off for all other data rates. Refer to Chapter 2 for switch settings. 4.2.
MT56DSU2 Owner’s Manual 4.3.1 Local Loopback Test This test allows you to test the local DTE and the local MultiDSU56K. Use the following steps to perform the Local Loopback Test. 1. Set DIP switch #9 to the down position. 2. The front panel Test (TM) LED lights, and if you send data from your DTE, it should be “looped back” to your DTE. If you have access to a Bit Error Rate Tester, this can be used in place of the DTE. DTE (Or BERT Tester) MultiDSU56K (In Local Loopback Test Mode) 4.3.
MT56DSU2 Owner’s Manual 4.3.3 Digital Loopback Test With Test Pattern Test This test allows you to test the local MultiDSU56K, the communications link, and the remote MultiDSU56K. Use the following steps to perform the Digital Loopback Test with the Pattern Test. With this test enabled, the MultiDSU56K sends and detects a pre-defined 15-bit pseudo-random test pattern. When an error is detected by the MultiDSU56K, the NS (No Signal) LED flashes. 1.
MT56DSU2 Owner’s Manual 4.3.5 DSU Loopback Test This test lets you verify proper DSU operation by matching a transmitted signal to the “loopedback” receive signal. Refer to Appendix B for cable description. 1. Obtain a DSU Loopback cable (#45640100) from Multi-Tech, or assemble one. Refer to Appendix B for instructions on building the Loopback cable. 2. Plug the Loopback cable into the back panel LINE jack. 3. If you send data from your DTE, it should be “looped back” to your DTE.
MT56DSU2 Owner’s Manual 4.3.6 DSU Back-to-Back Test This test lets you connect two DSUs with a back-to-back cable to verify proper DSU operation. Using a DSU that is known to be operational, you can test a second DSU that is suspect. 1. Obtain a DSU Back-to-Back cable (#45050000) from Multi-Tech, or assemble one. Refer to Appendix B for instructions on building the Back-to-Back cable. 2. Plug the cable into each DSU’s LINE jack. 3. On the “good” DSU, set DIP switch #9 to the down position. 4.
MT56DSU2 Owner’s Manual Chapter 5 – Service, Warranty and Tech Support Limited Warranty Multi-Tech Systems, Inc. (icMTSl,) warrants that its products will be free from defects in material or workmanship for a period of two years from the date of purchase, or if proof of purchase is not provided, two years from date of shipment. MTS MAKES NO OTHER WARRANTY, EXPRESSED OR IMPLIED, AND ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE HEREBY DISCLAIMED.
MT56DSU2 Owner’s Manual If you need to inquire about the status of the returned product, be prepared to provide the serial number of the product sent . Send DSUs to: MULTI-TECH SYSTEMS, INC.
MT56DSU2 Owner’s Manual Appendix A - Application Examples INTRODUCTION This section illustrates several types of applications in which the MultiDSU56K is typically used . These types include: • DDS point-to-point application, • DDS multipoint (polled) application, • Local Area Data Set, • External Clocking application, and • Analog Off-Net Extension application DDS POINT-TO-POINT APPLICATION In this application, the MultiDSU56K provides the interface between the DDS line and the DTE at your site.
MT56DSU2 Owner’s Manual DDS MULTIPOINT (POLLED) APPLICATION Since your Central Office (CO) equipment must include “Multipoint Junction Units” (MJU5) and other special arrangements for this type of service, you may need to coordinate efforts with your network service provider. The MultiDSU56K at the host end is the Master Station (also called the “Control Station”), which typically has RTS forced on. The attached MultiDSU56Ks are called “remote stations” and have RTS controlled by the DTE.
MT56DSU2 Owner’s Manual LOCAL AREA DATA SET APPLICATION In this application, two pairs of wires provide the connection between two MultiDSU56K devices. The two pairs can be up to the equivalent of 3 miles of 26 AWG wire at 56000 bps, or longer for subrate applications (see distances chart in section 3.4.1 of this manual). The figure below depicts a typical Local Area Data Set application.
MT56DSU2 Owner’s Manual ANALOG OFF-NET EXTENSION APPLICATION In this application, the MultiDSU56K is used with conventional analog modems and lines to complete DDS circuits in an area where DDS is not available (Site #3 in the example below) or where the customer requires an extension of the DDS circuit for a special application.
MT56DSU2 Owner’s Manual Appendix B - Interface Signals and Connector Pinouts DDS RJ48 CONNECTOR Pin 1 Pin 8 Key As viewed from the rear DESCRIPTION This connector ties the MultiDSU56K to the DDS Network. The RJ48 connector is keyed for proper insertion of a keyed RJ48 plug.
MT56DSU2 Owner’s Manual RS232C DB25S CONNECTOR 13 25 12 Transmitter Signal — 24 Element Timing 23 11 10 22 9 — Test Voltage (+V) 21 8 — Carrier Detect (CD) 20 7 — Signal Ground (SG) 19 6 — Data Set Ready (DSR) 18 5 — Clear To Send (CTS) Receive Clock (RC) — 17 4 — Request To Send (RTS) 16 3 — Received Data (RD) Transmit Clock (TC) — 15 2 — Transmit Data (SD) 14 1 As viewed from the rear DESCRIPTION This connector ties the MultiDSU56K to the DTE.
MT56DSU2 Owner’s Manual V.35 34-PIN CONNECTOR V.
MT56DSU2 Owner’s Manual LOOPBACK CABLE (MTS P/N 45640100) 1 8 DESCRIPTION This cable lets you test the MultiDSU56K when a second DSU is not available. It tests the DSU by having the DSU generate a signal, then the cable “loops” the signal back to the DSU for comparison to the original signal sent. You can order this cable (#45640100) from Multi-Tech, or build one using the instructions below. Refer to Chapter 4 for test procedures.
MT56DSU2 Owner’s Manual BACK-TO-BACK CABLE (MTS P/N 45050000) 1 8 DESCRIPTION This cable lets you test a suspect DSU by connecting it to a known good DSU. It tests the suspect DSU by connecting its Transmit signal to the good DSUs Receive circuits. You can order it from Multi-Tech (# 45050000), or build one using the instructions below. Refer to Chapter 4 for test procedures. SCHEMATIC 8 7 6 5 4 RJ48S 3 2 1 1 2 3 4 RJ48S 5 6 7 8 7" BUILD INSTRUCTIONS 1. 2. 3. 4. 5. 6. 7. 8.
MT56DSU2 Owner’s Manual Glossary This section defines several of the terms used in this manual. For an overview of DSU basics, refer to section 1.4 of this manual. A ALBO (Automatic Line Build Out) — part of the “equalizer” circuitry used to compensate for various gauges and alterations of local loops. Anti-Streaming — an option that prevents a streaming (jammed) DTE from affecting other devices on a multi-point network.
MT56DSU2 Owner’s Manual D Data Communications Equipment (DCE) — equipment that provides the function to establish, maintain and terminate a connection. Additionally, provides the signal conversion required for communications between DTE and data circuit or telephone line. See also “DTE”. DDS (Dataphone Digital Service) — AT&Ts private-line end-to-end digital service, with data rates (typically) at 2400, 4800, 9600, 19200, and 56000 bps. Now an AT&T “Accunet” family offering.
MT56DSU2 Owner’s Manual M master station — see “control station”. MJU (Multipoint Junction Unit) — a digital data bridge, located at telco office, for the DDS network. Used to combine remote station’s bit streams into one serial bit stream for transmission to the control station. Multi-drop — see “multipoint”. multipoint — a single line or circuit that connects several stations supporting terminals located in different areas. Usually requires some type of pooling method. Contrast “point-to-point”.
MT56DSU2 Owner’s Manual T test pattern — a diagnostic test for sending ,detecting and checking a pre-defined pattern of bits. two-wire circuit — A circuit in which one channel (line) is used for communications in both directions. Contrast ‘Iour-wire circuit”.
