Detailed descriptions
16.1 Motherboard
SIMATIC Rack PC 840 V2
Operating Instructions, Edition 05/2006, A5E00248055-04
16-5
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 hexagonal head screws.
COM 2 Serial Port (V24/Mouse), X31
The serial port (COM 2) has the following pinout:
COM 2 Serial Port (V24/Mouse)
Pin No.
Abbreviations
Meaning
Input /Output
1
DCD (M5)
Receiving signal level carrier
Input
2
RxD (D2)
Received data
Input
3
TxD (D1)
Transmitted data
Output
4
DTR (S1)
Data terminal ready
Output
5
GND (E2)
Functional ground (reference potential) –
6
DSR (M1)
Ready for operation
Input
7
RTS (S2)
Request to send
Output
8
CTS (M2)
Clear to send
Input
9
RI (M3)
Incoming call
Input
