Instruction Manual

HD132x Series User Manual

Appendix. RS232 Cable Connection

Signals of general RS232 9 pin connector:

Pin 1

Received Line Signal Detector (Data Carrier Detect) DCD

Pin 2

Received Data RxD

Pin 3

Transmit Data TxD

Pin 4

Data Terminal Ready DTR

Pin 5

Signal Ground GND

Pin 6

Data Set Ready DSR

Pin 7

Request To Send RTS

Pin 8

Clear To Send CTS

Pin 9

Ring Indicator RI

Table A. Signals of general RS232 9 Pin Connector

HD1320 and 1320E support RxD, TxD, RTS and CTS pins. If DTR and DSR are required for the flow

control, you can disconnect pins 1(DCD), 4(DTR), 6(DSR) of the RS232 connector as shown in Figure

6.1 to allow flow control communication with only RTS and CTS.

In case of HD1321, 5V TTL signal is provided for RS232 communication, and it supports RXD, TXD,

RTS, CTS, DTR and DRS signals.