Siemens SIMATIC Rack PC 840 Manual page 119

Adapter for COM1
You can convert the COM1 port of the SIMATIC PC family into the usual 25 pin
male connector by means of the enclosed adapter (25 pin / 25 pin). For this, you
only have to plug the adapter onto the COM1 socket and secure it with the two
hexagon head screws.
The V24 and TTY interfaces for COM1 can be alternately used.
COM 2 Serial Port (V24/Mouse), X31
The serial port (COM 2) on the Rack PC has the following pinout:
Figure 7-2 COM 2 Serial Port (Connector)
Pin No.
1
2
3
4
5
6
7
8
9
SIMATIC Rack PC 840 Manual
A5E00104826-03
5
9
6
1
Designation Description
DCD (M5) Receiving signal level
carrier
RxD (D2) Received data
TxD (D1) Transmitted data
DTR (S1) Terminal ready
GND (E2) Functional ground
(reference potential)
DSR (M1) Readiness for operation
RTS (S2) Switch on transmitter
CTS (M2) Ready to transmit status
RI (M3) Incoming call
Hardware Information
Input / Output
Input
Input
Output
Output
-
Input
Output
Input
Input
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