Siemens SIMATIC S7-400 Hardware And Installation Manual page 219

Table 8-7 Null Modem Cable for Connecting a CPU via IF to the COM Interface of a
Programming Device with 9-pin Sub. D Male Connector, continued
Signal
S1 / DTR
E2 / GND
M1 / DSR
S2 / RTS
M2 / CTS
M3 / RI
9-pin sub.
D female conn.
(COM1 for IF)
If the free COM interface of your programming device has a 25-pin subminiature D
connector, you can use Table 8-8 below for the pin assignments of the null modem
cable.
Table 8-8 Null Modem Cable for Connecting a CPU via IF to the COM Interface of a
Programming Device with 25-pin Sub. D Male Connector
Signal
E1 / GND
M5 / DCD
D2 / RxD
D1 / TxD
S1 / DTR
E2 / GND
M1 / DSR
S2 / RTS
M2 / CTS
M3 / RI
9-pin sub.
D female conn.
(COM1 for IF)
S7-400 and M7-400 Programmable Controllers, Installation Manual
C79000-G7076-C424-01
www.gkbpx.com
Pin Connection
4 connected to
5 connected to
6 connected to
7 connected to
8 connected to
9 -
Pin U = housing (shield)
Length: 10 m max.
Pin Connection
U connected to
1
2 connected to
3 connected to
4 connected to
5 connected to
6 connected to
7 connected to
8 connected to
9
Pin U = housing (shield)
Length: 10 m max.
Assembling the M7-400
Pin
6
5
4
8
7
9
D female conn.
Pin
U
-
8
2
3
6
7
20
5
4
-
22
Signal
M1 / DSR
E2 / GND
S1 / DTR
M2 / CTS
S2 / RTS
M3 / RI
9-pin sub.
(COMx for
programming
device)
Signal
E1 / GND
M5 / DCD
D2 / RxD
D1 / TxD
M1 / DSR
E2 / GND
S1 / DTR
M5 / CTS
S2 / RTS
M3 / RI
25-pin sub.
D male conn.
(COMx for
programming
device)
8-37