C9900-E209 with RS232 interface

The module for electrical isolation of an RS232 interface of the motherboard is led out via a 9-pin standard DSUB connector in a bracket. The interface features overvoltage protection. If an overvoltage occurs, the channel is switched off.

C9900-E209 with RS232 interface 1:Fig.14: RS232 interface pin numbering
RS232 interface pin numbering

Pin

Name

Description

1

DCD

Data Carrier Detect

2

RXD

Receive Data

3

TXD

Transmit Data

4

DTR

Data Terminal Ready

5

GND

Ground

6

DSR

Data Set Ready

7

RTS

Request to Send

8

CTS

Clear to Send

9

RI

Ring Indicator