Assembling the M7-400
8-37
S7-400 and M7-400 Programmable Controllers Hardware and Installation
A5E00069481-04
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
Signal
Pin
Connection
Pin
S1 / DTR
4
connected to
6
M1 / DSR
E2 / GND
5
connected to
5
E2 / GND
M1 / DSR
6
connected to
4
S1 / DTR
S2 / RTS
7
connected to
8
M2 / CTS
M2 / CTS
8
connected to
7
S2 / RTS
M3 / RI
9
-
9
M3 / RI
9-pin sub.
D female conn.
(COM1 for IF)
Pin U = housing (shield)
Length: 10 m max.
9-pin sub.
D female conn.
(COMx for
programming
device)
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
Pin
Connection
Pin
Signal
E1 / GND
U
connected to
U
E1 / GND
M5 / DCD
1
-
8
M5 / DCD
D2 / RxD
2
connected to
2
D2 / RxD
D1 / TxD
3
connected to
3
D1 / TxD
S1 / DTR
4
connected to
6
M1 / DSR
E2 / GND
5
connected to
7
E2 / GND
M1 / DSR
6
connected to
20
S1 / DTR
S2 / RTS
7
connected to
5
M5 / CTS
M2 / CTS
8
connected to
4
S2 / RTS
M3 / RI
9
-
22
M3 / RI
9-pin sub.
D female conn.
(COM1 for IF)
Pin U = housing (shield)
Length: 10 m max.
25-pin sub.
D male conn.
(COMx for
programming
device)