Black Box Short-Haul Modem B manuale d’uso

AUGUST 2000 ME800A ME800A-R2 ME805-C ME805-C-R2 ME810 Short-Haul Modem B (SHM-B Async) CUSTOMER SUPPORT INFORMATION 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, Law[...]

1 SHM-B ASYNC 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. It has been te[...]

2 SHM-B ASYNC NORMAS OFICIALES MEXICANAS (NOM) ELECTRICAL SAFETY STATEMENT INSTRUCCIONES DE SEGURIDAD 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 [...]

3 SHM-B ASYNC 10. El equipo eléctrico deber ser situado fuera del alcance de fuentes de calor como radiadores, registros de calor, estufas u otros aparatos (incluyendo amplificadores) que producen calor . 11. El aparato eléctrico deberá ser connectado a una fuente de poder sólo del tipo descrito en el instructivo de operación, o como se indiqu[...]

4 SHM-B ASYNC TRADEMARKS USED IN THIS MANUAL Any trademarks mentioned in this manual are acknowledged to be the property of the trademark owners.[...]

5 SHM-B ASYNC 1. Specifications Transmission — Data Rate (bps) Distance (miles/km) 19,200 1/1.6 9600 2/3.2 4800 3/4.8 2400 4/6.4 NOTE: The above specifications are valid for 24- or 26-AWG unshielded twisted-pair telephone cable insulated by polyethylene with a mutual capacitance of 0.083 µf/mile. Shielded twisted-pair cable will reduce the dista[...]

6 SHM-B ASYNC end of the loop. Interface is switch-selectable for DTE/DCE configuration (pins 2 and 3 are reversed) Connectors — (1) DB25 female, (1) 5-screw terminal block Diagnostics — Loopbacks provided by a front-panel switch: Analog loopback on a 4-wire loop and digital loopback on equipment interface (EIA-232) Status Indication — Two bi[...]

7 SHM-B ASYNC Primary: 115 VAC ±10%, 60 Hz, 5 watts (12 watts max.); Primary: 230 VAC ±10%, 50/60 Hz; Secondary: 17 VAC, 700 mA Size — Standalone: 1.4"H x 4.25"W x 4.5"D (3.8 x 10.9 x 11.7 cm); Rackmount: 5.25"H x 17"W x 9"D (13 x 43 x 23 cm) Weight — Standalone: 1.3 lb. (0.6 kg), including transformer; Rackmount[...]

8 SHM-B ASYNC 2. Introduction The Short-Haul Modem Model B Async (SHM-B Async) is an asynchronous full-duplex 4-wire line driver/receiver which allows two EIA-232 devices to communicate at distances of up to 4 miles and at data speeds of up to 19,200 bps. In addition to the transmitter and receiver circuits, the SHM-B Async includes EIA-232 control[...]

9 SHM-B ASYNC 3. Installation Installation involves three basic steps: four-wire connections; EIA-232 connection; switch settings. 3.1 Four-Wire Connections Figure 1 shows the location of the terminal block on the circuit board. Refer to Figure 2 to make the proper connections between two SHM-B units. NOTE: Transmit + (TX+) on one modem is wired to[...]

10 SHM-B ASYNC 5. Insert the wires into the terminal strip; tighten the screw terminals. 6. After you have made all four connections, wrap the nylon cable tie (packaged with the SHM-B) around the wires. Pull the tie tight around the wires to secure them to the printed circuit board. Trim the excess nylon tie with wire cutters or scissors. Figure 1.[...]

11 SHM-B ASYNC Figure 2. Wiring diagram for two SHM-B units. 3.2 EIA-232 Connection Connect the SHM-B to your computer or terminal with a standard EIA-232 cable and DB25 connectors. Refer to your equipment’s installation manual if you need information on the exact EIA-232 signals required for your equipment. Often, it is best to use only the Tran[...]

12 SHM-B ASYNC Table 1. EIA-232 Pin Connections on SHM-B Pin Number Signal Name 1 Protective Ground 2 Transmit Data/Receive Data (TD/RD)* 3 Receive Data/Transmit Data (RD/TD)* 4 Request to Send (RTS) 5 Clear to Send (CTS) 6 Data Set Ready (DSR) 7 Signal Ground 8 Carrier Detect (CD) 20 Data Terminal Ready (DTR) *TD and RD can be reversed using the D[...]

13 SHM-B ASYNC information concerning its DTE/DCE setting. Table 2 gives the EIA-232 pinning of the SHM-B with the DTE/DCE switch in the DCE position. Table 2. Pinning with DTE/DCE switch in the DCE position. PIN NUMBER SIGNAL NAME DIRECTION 1 Protective Ground ————— 2 Transmitted Data TD* To DCE 3 Received Data RD* From DCE 4 Request to [...]

14 SHM-B ASYNC 3.4 Flow Control The SHM-B uses a clever, yet simple way to allow this unit to work with a broad line of equipment. S TANDARD EIA-232C H ANDSHAKING (RTS/DTR C ONTROL J UMPER IN EN P OSITION ) The individual SHM-B modems force their own DTR, RTS, CTS, and DSR control lines HIGH (>+3V) when: • The twisted-pair wires are installed [...]

15 SHM-B ASYNC Because DTR, DSR, RTS, and CTS are tied together internally, dropping any one of these four signals to a negative state will also drop DCD on the remote side to a negative state. DCD will also go LOW if the remote SHM-B is powered down, or if the twisted-pair wire is broken. X-ON/X-OFF M ODE (RTS/DTR C ONTROL J UMPER IN DIS P OSITION[...]

16 SHM-B ASYNC 4. Operation After completing the wiring and configuration procedure, slide the printed circuit card back into the case while pulling the data and power cables through the holes in the back panel. The front panel will snap into the front of the case when the printed circuit board has been completely pushed to the back of the case. Co[...]

17 SHM-B ASYNC When in loopback mode, the switch button indicator will appear to the sender. If a CRT terminal is connected to the SHM-B, typing characters on the keyboard should result in the same characters appearing on the CRT screen. If no characters appear, check your EIA-232 connections and the setting of S1. See Figure 3 for an illustration [...]

18 SHM-B ASYNC 5. Rackmount Installation The SHM-B Async Card is a rack mount unit (ME805-C) that installs in a standard 19-inch panel rack. (You can use the SHM-B Rack [ME810], which can hold up to 16 cards.) The SHM-B Async Card will occupy 5.25 inches of vertical rack space, and is 9 inches deep. To install the SHM-B Rack, first remove the acryl[...]

19 SHM-B ASYNC easiest access to the terminals, switches, etc. After a SHM-B Card is wired, it can then be inserted into an open slot in the SHM-B rack. Be certain that the circuit board has mated with the power pins on the SHM-B rack before applying force to fully seat the board ; otherwise you may damage the board and power pins. When all boards [...]

20 SHM-B ASYNC 6. T roubleshooting Guide The following information will help you troubleshoot your installation if problems develop. If your particular situation isn’t listed here, call Technical Support for assistance. Have ready a description of the problem with your installation, your DTE equipment make and models, your equipment’s DTE/DCE c[...]

21 SHM-B ASYNC printed circuit board is properly inserted and fully seated against the motherboard of the rack. SYMPTOM: No data transfer in one or both directions (to, from, or to-and-from the SHM-B). 1. Monitor the TD LED on the sending-end modem while sending data. The light should flash red/green. If not, check the DCE/DTE switch on that unit. [...]

22 SHM-B ASYNC Pins 4, 5, 6, 8, and 20 should all be HIGH to enable communication. 5. If pin 8 (Carrier Detect) is low, this indicates: • a defective transmission line or connection • a defective remote SHM-B • remote SHM-B without power SYMPTOM: TD and RD LEDs indicate data activity, but data communication doesn’t exist. 1. Check the wirin[...]

23 SHM-B ASYNC computing equipment for consistency. 3. Wire the SHM-B units back-to-back, eliminating the twisted-pair; see if you still have errors. • If you do have errors, then test each SHM individually in the following way: loopback one SHM’s Transmit-to-Receive by using two short pieces of wire. Connect that SHM to a dumb terminal and key[...]

24 SHM-B ASYNC 3. Check the path of your four-wire circuit for potential sources of interference (fluorescent lighting, electrical motors, etc.). Such sources of electrical “noise” can provide an environment in which unwanted signals are induced onto your four-wire circuit. Also, check to see if an adjacent four-wire cable carrying a separate d[...]

25 SHM-B ASYNC SYMPTOM: TD or RD indicator is steadily on red with no data attempting to pass (no DTEs attached). Check for reversal of polarity on the four-wire connection.[...]

1000 Park Drive • Lawrence, PA 15055-1018 • 724-746-5500 • Fax 724-746-0746 © Copyright 2000. Black Box Corporation. All rights reserved.[...]