Siemens SIMATIC IOT2040 - Page 53

Technical specifications
7.5 Hardware descriptions
SIMATIC IOT2020, SIMATIC IOT2040
Operating Instructions, 10/2016, A5E37656492-AB
53
Assignment RS 232
Pin
Short description
Meaning
1
DCD
Data carrier detect (I)
2 RxD Received data (I)
3
TxD
Transmitted data (O)
4 DTR Data terminal ready (O)
5
M
Ground
6
DSR
Data set ready (I)
7
RTS
Request to send (O)
8
CTS
Clear to send (I)
9
RI
Incoming call (I)
Assignment RS 422
Pin
Short description
Meaning
1
TX-
Transmitted data - (O) for full-duplex mode
2
TX+
Transmitted data + (O) for full-duplex mode
3
RX+
Receive data + (I) for full-duplex mode
4
RX-
Receive data - (I) for full-duplex mode
5
M
Signal ground
6
nc
7
nc
8
nc
9
nc
Assignment RS 485
Pin
Short description
Meaning
1
Data-
Transmit / receive data - (I/O) for half-duplex mode
2
Data+
Transmit / receive data+ (I/O) for half-duplex mode
3
nc
4
nc
5 M Signal ground
6
nc
7
nc
8
nc
9
nc