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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, Lawrence, PA 15055-1018
Web site: www.blackbox.com • E-mail: info@blackbox.com
NORMAL
TD RD
LOOPBACK
ASYNC SHORT HAUL MODEM
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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 tested and found to comply with the limits for a Class A computing device in accordance with the specifications in Subpart J of Part 15 of FCC rules, which
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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 aparato eléctrico y en sus instrucciones de operación deben ser respetadas. 4. Todas las instrucciones de operación y uso deben ser seguidas. 5. El aparato el
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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 indique en el aparato. 12. Precaución debe ser tomada de tal manera que la tierra fisica y la polarización del equipo no sea eliminada. 13. Los cables de la fuente
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SHM-B ASYNC TRADEMARKS USED IN THIS MANUAL Any trademarks mentioned in this manual are acknowledged to be the property of the trademark owners. 4
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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 distance to one-third of the table value, due to the additional capacitance contributed by the cable’s shielding. Actual distances may vary depending on your sp
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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-color LEDs indicate the status of the transmitter and receiver. A green light indicates a “low” logic level (-3 to -25V) on the EIA-232 interface; a red ligh
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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: 3.7 lb. (1.7 kg), including transformer 7
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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 line interfaces, status monitor LEDs, and a loopback switch. The SHM-B is available in both a standalone version (ME800A) and a rackmount version (ME80
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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 Receive + (RX+) on the other modem; Transmit - (TX-) is wired to Receive - (RX-). A ground connection is optional. 1. If the unit is assembled, separat
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RX+ RX- TX+ TX- GROUND 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. J1 RS-232 CONNECTOR EN JUMPER DIS RTS/DTR DCE CONTROL DTE/DCE DTE S2 (LOOPBACK) Figure 1. SHM-B board; 5-screw terminal block. 10
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SHM-B ASYNC TX+ RX+ TX- RX- RX+ TX+ RX- TX- SHM #1 SHM #2 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 Transmit Data (TD), Receive Data (RD), and ground lines if your equipment does not require the use of the control
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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 DTE/DCE switch, S1 on the circuit board. See Section 3.3 for details. 3.3 Switch Settings Refer to Figure 1 in this chapter. Switch S1 is used to reverse
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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 Send (RTS) To DCE 5 Clear to Send (CTS) From DCE 6 Data Set Ready (DSR) From DCE 7 Signal Ground ————— 8 Received Line Signal Detector From DCE 20 Data Terminal Re
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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. STANDARD EIA-232C HANDSHAKING (RTS/DTR CONTROL JUMPER IN EN POSITION) The individual SHM-B modems force their own DTR, RTS, CTS, and DSR control lines HIGH (>+3V) when: • The twisted-pair wires are installed correctly. • Power is applied to both modems. • No computer devices are attached to the modems. This forces DCD HIGH on the remote modem; thus, the remote modem kno
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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 MODE (RTS/DTR CONTROL JUMPER IN DIS POSITION) If X-ON/X-OFF characters are used for handshaking control, rather than hardware logic levels, move the RTS/DTR control jumper to the DIS position. Typicall
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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. Connect the SHM-B to your equipment, then plug the wall transformer into its power source. Check the SHM- B operation at both ends of the loop by pressing
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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 of the loopback mode. The TD and RD LEDs on the front panel of your SHM-B indicate the status of the SHM-B transmitter and receiver, respectively. Green
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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 acrylic front panel by pulling out the six plunger latches on the front of the panel, then pulling on opposite-side plungers to loosen and remove the panel. L
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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 have been wired and plugged into the rack, plug the wall transformer into its power source. You should be able to communicate as described in Chapter 4. W
