Installation manual
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 SignalPinConnectionPin
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)