Pelco cs73m-d operation manual Connecting the MDA to AN External PC

NOTE: The CM9760-MDA is configured at the factory for RS-422 communication. To communicate via RS-232, an internal DIP switch must be changed. Refer to the Communication Ports Setup section.

NOTE: The pin numbering of the wall block shown in Figure 5 applies to the Pelco RJ-45 wall block. A wall block purchased from a supplier other than Pelco may have a different pin numbering scheme.

CONNECTING THE MDA TO AN EXTERNAL PC

Perform this step if you are going to program your CM9760-MDA unit using a PC (personal computer).

Refer to Figure 5 and make a cable to connect the MDA to the PC. The figure shows a typical nine-pin sub ÒDÓ connector for the PCÕs COM 1/COM 2 serial port. Computers may differ regarding connector types and pin-outs. Therefore, always refer to the computerÕs manual to determine proper pin-outs.

If more than one MDA is to be programmed using a PC, note the following:

¥A maximum of 16 MDA units can be daisy-chained. To daisy-chain up to 16 MDA units, connect the RS-422 output of the first MDA unit to the RS-422 input of the second MDA unit and continue this method until the last MDA unit is connected (refer to Table D and to Figure 39).

¥If more than 16 MDAs are to be connected to a PC, a CM9760-CDU-T must be used. Refer to Figure 40 for an example of connecting over 16 MDAs to a PC. Note that a maximum of 64 MDA units can be connected to a PC for programming.

Table D. MDA RJ-45 Connector Pin-Outs

Pin Out	RS-232 Function	RS-422 Function	RS-485 Function
1	Transmit	Transmit +	Transmit +
2	No Connection	Transmit -	Transmit -
3	No Connection	No Connection	No Connection
4	Ground	Ground	Ground
5	Ground	Ground	Ground
6	No Connection	No Connection	No Connection
7	No Connection	Receive -	Receive -
8	Receive	Receive +	Receive +

						MDA SIDE
							CM9760-MDA
				14	15	16			PIN 8	PIN 1
						PGM		120V A
						MON
		PC SIDE
							COM1	COM2		COM1 RJ-45
							UNI T			CONNECTOR
				REVERSED CABLE				RJ-45
COMPUTER				COMPUTER
								CONNECTOR
TRANSMIT				RECEIVE
									REVERSED CABLE CONNECTIONS
5	4	3	2	1		8		1	WALL BLOCK	CM9760-MDA
									RJ-45	RJ-45
						7		2	CONNECTOR	CONNECTOR
9		8	7	6					PIN 1=TX	PIN 1=TX
						6		3
						5		4	PIN 8=RX	PIN 8=RX
			GROUND				WALL BLOCK

Figure 5. PC Connection to CM9760-MDA

12 Pelco Manual C573M-D (11/03)