Pelco C1977M-D User Manual

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      Pelco Manual C1977M-D (6/02)

The unit has two serial interfaces—one at the back and another at the front. They serve different purposes
and cannot be used interchangeably, as explained in the following.

For local control and configuration of the unit, you can connect a data terminal (for example, a PC running
a standard terminal program) to the serial interface labeled Control Terminal on the rear panel. The 9-pin
DSUB connector features a standard RS-232 interface that can be connected to a PC’s COM port.

You can use a standard terminal program to communicate with the unit. The default parameters are set to
19200 baud with 8 bits of data, 1 stop bit and no parity bit (8N1).

To access the online help, type ? (a question mark) in the terminal window. For more information on the
command set, see the 

 section. This mode allows the control port to be used to send serial

data that requires flow control.

You can configure the RS-485 halfduplex mode in the web browser. The RTS and CTS signals are enabled
for flow control.

If this RS-485 mode is chosen, the camera control data is transferred automatically to the Control Terminal
port. Certain cameras with fixed data length require the buffered RS-485 mode. (This halfduplex mode is
not required for interfacing to any Pelco product.)

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6   7   8   9

VIEWED FROM SOLDERING

SIDE OF PLUG

1

2

3

4

5

6

7

8

9

DCD

RXD

TXD

DTR

GND

DSR

RTS

CTS

-

Input

Input

Output

Output

Input

Output

Input

-

Data Carrier Detect

Receive Data

Transmit Data

Data Terminal Ready

Ground

Data Set Ready

Ready To Send

Clear To Send

-

Figure 20.  Control Terminal Port Pin Assignments in RS-232 Mode