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ASM-20
Synchronous/Asynchronous Short Range Modem
Installation and Operation Manual
Notice
This manual contains information that is proprietary to RAD Data Communications. No part of this
publication may be reproduced in any form whatsoever without prior written approval by RAD Data
Communications.
No representation or warranties for fitness for any purpose other than what is specifically mentioned in
this manual is made either by RAD Data Communications or its agents.
For further information co
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Warranty This RAD product is warranted against defects in material and workmanship for a period of one year from date of shipment. During the warranty period, RAD will, at its option, either repair or replace products which prove to be defective. For warranty service or repair, this product must be returned to a service facility designated by RAD. Buyer shall prepay shipping charges to RAD and RAD shall pay shipping charges to return the product to Buyer. However, Buyer shall pay all shipping ch
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Safety Warnings The exclamation point within a triangle is intended to warn the operator or service personnel of operation and maintenance factors relating to the product and its operating environment which could pose a safety hazard. Always observe standard safety precautions during installation, operation and maintenance of this product. Only a qualified and authorized service personnel should carry out adjustment, maintenance or repairs to this instrument. No adjustment, maintenance or repair
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Regulatory Information FCC-15 User Information This equipment has been tested and found to comply with the limits of the Class A digital device, pursuant to Part 15 of the FCC rules. These limits are designed to provide reasonable protection against harmful interference when the equipment is operated in a commercial environment. This equipment generates, uses and can radiate radio frequency energy and, if not installed and used in accordance with the instruction manual, may cause harmful interfe
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Declaration of Conformity Manufacturer’s Name: RAD Data Communications Ltd. Manufacturer’s Address: 12 Hanechoshet St. Tel Aviv 69710 Israel declares that the product: Product Name: ASM-20 Conforms to the following standard(s) or other normative document(s): EMC: EN 55022 (1994) Limits and methods of measurement of radio disturbance characteristics of information technology equipment. EN 50082-1 (1992) Electromagnetic compatibility - Generic immunity standards for residential, commercial and lig
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Quick-Start Guide 1. Installing and Operating ASM-20 If you are familiar with ASM-20, use this guide to prepare it for operation. Perform the following steps for both the local and the remote units. 1. Disconnect all cables from the units. 2. Open the units. 3. Adjust the jumpers. See Chapter 2, Installation and Setup. Make sure that there is only one clock source in the application: one modem Note INT or EXT and the other modem RCV (LBT). 4. Configure the DTE parameters. See Chapter 2, Instal
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Preface Foreword This manual provides information on the technical characteristics, installation and operating instructions of ASM-20. The manual contains the following information: Chapter 1. Introduction describes ASM-20 and its applications, features, options, physical and functional descriptions and technical specifications. Chapter 2. Installation describes the information required to implement the mechanical and electrical installation of the ASM-20 standalone model, including the inform
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Conventions A note draws attention to a general rule for a procedure, or to Note exceptions to a rule. A caution warns of possible damage to the equipment if a Caution procedure is not followed correctly. A warning alerts to the presence of important operating and maintenance (servicing) instructions in the literature accompanying the equipment. If these instructions are not Warning followed exactly, possible bodily injury may occur.
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Contents CHAPTER 1 INTRODUCTION 1.1 Overview .......................................................................................................................1-1 Applications..........................................................................................................................1-1 Features................................................................................................................................1-2 Options ..............................................
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Contents 3.2 Controls and Indicators...................................................................................................3-1 3.3 Operating Instructions ....................................................................................................3-3 Power On Procedure ............................................................................................................3-3 Activation of Tests ...............................................................................
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List of Figures Figure 1-1 Point-to-point Application ...........................................................................................1-1 Figure 1-2 G.703 Modem Link Application ..................................................................................1-2 Figure 1-3 Tail-end for Digital Network Application......................................................................1-2 Figure 1-4 ASM-20, General View.............................................................
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List of Tables Table 1-1 Approximate Range.......................................................................................................1-9 Table 2-1 ASM-20 Strap Selection Settings ....................................................................................2-5 Table 2-2 Async Character Length Setting .....................................................................................2-6 Table 3-1 Control and Indicator Functions .............................................
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Chapter 1 Introduction 1.1 Overview The ASM-20 Short Range Modem operates synchronously or asynchronously at full or half duplex, over unconditioned lines. ASM-20 has a range of up to 23 km (14 miles) and operates at selectable data rates from 19.2 kbps to 256 kbps. ASM-20 uses conditioned diphase modulation (EUROCOM Std. D1) to provide immunity from background noise, eliminate normal line distortion and enable efficient transmission and reception of serial data over a twisted pair cable. Tran
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Chapter 1. Introduction ASM-20 Installation and Operation Manual RAD ASM -20 RCV CLK G.703 DTE DIGITAL RAD SERVICE RAD NETWORK ASM-20 ASM-20 EXT CLK EXT CLK RAD ASM -20 RCV CLK Term ina l Figure 1-2 G.703 Modem Link Application RAD RAD G.703 or ASM-20 ASM-20 X.21/RS-530/V.24 or V.35 or ETH DTE Figure 1 -3 Tail-end for Digital Network Application ASM-20 features V.54 diagnostic capabilities for performing local analog Features loopback and local and remote digital loopback. The operator at
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ASM-20 Installation and Operation Manual Chapter 1. Introduction Connection to an RS-449/V.36 interface is accomplished via the RS-530 interface (see Appendix A, Ethernet Interface). ASM-20 incorporates a built-in Bit Error Rate Tester (BERT). The internal BERT allows complete testing of both modems and the line without external test equipment. A front panel switch generates a pseudo-random test pattern (511-bit, according to ITU/V.52) for testing end-to-end connectivity. The ERROR LED will fl
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Chapter 1. Introduction ASM-20 Installation and Operation Manual DTE XM T RCV GND ~230 V/ 0.1A T 250V Figure 1 -5 ASM-20 Rear Panel with V.35 Interface 1.3 Functional Description This section contains functional descriptions of the circuit blocks in ASM-20, primarily those circuits which are required for configuring the modem (see Figure 1-6). Figure 1-6 ASM-20 Block Diagram The encoder receives data from the DTE, then modulates the data using the Encoder CDD “conditional diphas
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ASM-20 Installation and Operation Manual Chapter 1. Introduction This circuit supplies the transmit clock to the encoder. Three clock sources Modulation are available: Timing • Internal oscillator • External from the DTE • Loop clock derived from the receive signal. Setting the XMT CLK jumper determines the timing option. See Setting Internal Jumpers and Switches in Chapter 2 for more information. Two options are available for the XMT level (signal level): 0 and -6 dBm. XMT Level XMT level
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Chapter 1. Introduction ASM-20 Installation and Operation Manual characters. The remote converter will add a shorter stop bit (shorter by 12.5% or 25%) before sending the data to the remote DTE. A suitable operation of the ASYNC to SYNC converter is selected by adjusting the proper character length and frequency deviation setting (dip switch bank), see Figure 2-3 and Table 2-2. To allow tail-end connection on an X-21 interface, a buffer is provided on X.21 Buffer (for received data. When ASM-2
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ASM-20 Installation and Operation Manual Chapter 1. Introduction Type • V.24/RS-232 via 25-pin D-type, (up to 64 kbps Digital Interface only), female connector • V.35 via 34-pin female connector • X.21 via 15-pin D-type female connector • RS-530 (RS-422) via 25-pin D-type female connector • V.36 (RS-449) via 37-pin female connector using mechanical cable adapter provided with the product • G.703 Codirectional (64 kbps) via terminal block or RJ-45 • Built-in Ethernet bridge via RJ-45 connector
