Siemens S7-400 ユーザーズマニュアル

13-11

S7-400, M7-400 Programmable Controllers Module Specifications
A5E00069467-07

Table 13-8

Socket X1, X2 IF 962-COM (9-Pin Sub D Plug Connector)

1

DCD

Receive signal level

Input

2

RxD

Receive data

Input

3

TxD

Transmitted data

Output

4

DTR

Data terminal ready

Output

5

Signal GND

Operational ground (GND

int

)

–

6

DSR

Data set ready

Input

7

RTS

Request to send

Output

8

CTS

Clear to send

Input

9

RI

Ring indicator (incoming call)

Input

Operational ground (signal GND) at the COMa or COMb ports is referenced to
internal ground.

Suitable measures may be required on the process side to avoid ground loops.