ASM-20 Sync/Async Short Range Modem FEATURES • Full or half duplex • Modular, field changeable • Carrier control option operation digital interfaces available • V.54 diagnostic loops are: V.24, V.35, X.21, • Synchronous or available RS-530, V.36, G.703 Asynchronous • Internal test pattern Codirectional and built-in • Selectable data rates from generator and error LED Ethernet bridge 19.2 to 256 kbps • Line protection circuit • Range up to 23 km / 14 miles ASM-20 Sync/Async Short Range Modem DESCRIPTION Table 1. Approximate Maximum Range Baud 19 AWG 22 AWG 24 AWG 26 AWG • The ASM-20 Short Range Rate (0.8 mm) (0.6 mm) (0.5 mm) (0.4 mm) Modem operates synchronously kbps km miles km miles km miles km miles or asynchronously (strap- selectable) at full or half duplex 256 3.75 2.3 2.85 1.75 2.25 1.4 1.9 1.2 over unconditioned lines. It has a 192 6.0 3.7 4.5 2.8 3.5 2.2 2.7 1.7 range of up to 23 km (14 miles) and operates at data rates from 144 10.6 6.6 6.75 4.2 4.5 2.8 3.4 2.1 19.2 kbps up to 256 kbps. 128 12.4 7.7 7.3 4.5 5.0 3.1 3.6 2.2 • The use of conditioned diphase 115.2* 12.8 7.8 7.65 4.75 5.25 3.3 3.8 2.5 modulation (EUROCOM Std. D1) provides immunity to 112 12.8 8.0 8.0 5.0 5.5 3.4 4.0 2.5 background noise, eliminates 96 13.0 8.1 8.3 5.15 6.0 3.7 4.15 2.6 normal line distortion and enables efficient transmission 72 15.0 9.3 9.4 5.8 6.25 3.9 4.3 2.65 and reception of serial data over twisted pair cable. Transmit 64 17.6 11.0 11.0 6.8 7.5 4.6 5.3 3.3 timing is provided internally, or is 57.6* 18.8 11.7 11.75 7.3 8.0 5.0 5.6 3.5 derived externally from the data terminal or receive signal. 56 18.8 11.7 11.75 7.3 8.0 5.0 5.6 3.5 Receive timing is regenerated 48 19.4 12.0 12.2 7.6 8.25 5.2 5.8 3.6 from the data. 38.4* 20 12.5 12.5 7.8 8.5 5.3 6.0 3.7 • When set to async mode, ASM-20 performs async to sync 32 20.5 12.75 12.85 8.0 8.75 5.4 6.2 3.85 conversion in compliance with 28.8* 20.5 12.75 12.85 8.0 8.75 5.4 6.2 3.85 ITU V.14 standard. Table 1 details the rates relevant for 19.2** 23.0 14.0 14.0 8.7 9.75 6.0 7.0 4.3 sync and async. Rates higher than * Asynchronous baud rates 115.2 kbps are supported in ** Sync/Async sync mode only. APPLICATION Figure 1. Tail-end for Digital Network Application ASM-20 Sync/Async Short Range Modem SPECIFICATIONS • Data Rates − selectable • ASM-20 features V.54 diagnostic Sync: capabilities to perform local 19.2, 32, 48, 56, 64, 72, 96, analog loopback, and local and • Transmission Line 112, 128, 144, 192, 256 kbps remote digital loopback. The Type: Unloaded twisted Async: loops can be manually activated pair 19 to 26 AWG 19.2, 28.8, 38.4, 57.6, from the front panel or via Range: See Table 1 115.2 kbps control signals from the interface Level: Strap-selectable connector. In addition, ASM-20 • Diagnostics incorporates a built-in Bit Error 0 dBm or -6 dBm Comply with V.54 standard Rate Tester (BERT) to enable Impedance:150Ω or low Digital loopback: complete testing of both Return loss: Greater than 15 dB − Local (DIG), activated by modems and the line. A front Carrier: Controlled by RTS manual switch panel switch generates a or constantly On − Remote (REM), activated by pseudo-random test pattern (511 manual switch or by control Modulation: Conditioned bits) according to signal from the DTE interface diphase European ITU V.52, for testing end-to-end connector Std. D1 connectivity. An ERROR LED Analog loopback: flashes when a bit error is • Digital Interface Local (ANA), activated by detected. − V.24/RS-232 via 25-pin manual switch or by control D-type, (up to 64 kbps only) • ASM-20 is available as a signal from the DTE interface female connector desktop unit or as a card for the connector − V.35 via 34-pin, ASM-MN-214 modem rack. The Pattern: female connector rack can carry up to 14 ASM-20 Test pattern activated by cards and is supplied with 25-pin − X.21 via 15-pin D-type, manual switch D-type connectors. female connector • Timing Elements − RS-530 (RS-422) via 25-pin • Optional hardware is available Receive clock: D-type, female connector for mounting one or two Derived from the receive − V.36 (RS-449) via 37-pin, standalone units in a 19” rack. signal female connector using Transmit clock: mechanical cable adapter Derived from 3 alternative provided with the product sources: − G.703 Codirectional − Internal oscillator (64 kbps) via terminal block − External from the DTE or RJ-45 (see Ordering) − Loop clock derived from the − Built in Ethernet bridge via receive signal RJ-45 connector or BNC Figure 2. Point-to-point Application ASM-20 Sync/Async Short Range Modem ORDERING RM-17 • Indicators PWR (green): Power Hardware for mounting one or two RTS (yellow): Request to Send standalone units in a 19” rack ASM-20-2/*/+/# TD (yellow):Transmit Data CIA/& RD (yellow):Receive Data Short range modem, stand alone Connector Interface Adapter for the DCD (yellow): Data Carrier unit ASM-MN-214 19” rack Detect ASM-20-2R/+ TEST (red): Test & Specify CIA connector option: Short range modem card for the ERR (yellow): Bit Errors V35/1 for adapting one modem ASM-MN-214 19” rack • Power Supply card’s 25-pin connector into 115 or 230V (±10%) * Specify power supply one V.35, 34-pin connector 47 to 63 Hz; 5W 115 for 115 VAC X21 for adapting two adjacent -48 VDC or 24 VDC 230 for 230 VAC modem cards’ 25-pin 48 for -48 VDC • Physical connectors to two X.21, 15- 24 for 24 VDC pin connectors ASM-20 Modem: Height: 44 mm/ 1.7 in + Specify interface Width: 215 mm/ 8.5 in V24 for V.24/RS-232 Depth: 243 mm/ 9.6 in (up to 64 kbps) Weight: 1.4 kg / 3.1 lb V35 for V.35 530 for RS-530 ASM-20-R Card: X21 for X.21 Dimensions: V36 for V.36/RS-449 Fits ASM-MN-214 modem rack 703 for G.703 Codirectional Weight: 360g / 10.1 oz (64 kbps) • Environment UTP for built-in Ethernet bridge, Temperature: 0-50°C / 32-122°F 10BaseT with RJ-45 Humidity: up to 90%, BNC for built-in Ethernet bridge, non-condensing 10BaseT with BNC connector Note: When using V.35 or X.21 interfaces for ASM-20-2R, the CIA adapter is required. # Specify G.703 Codirectional connector TB for terminal block connector RJ for RJ-45 connector 601-100-01/99  1999 RAD Data Communications Ltd. Specifications are subject to change without prior notice.