Siemens SIMATIC CP 440 Manual page 157

Connecting Cable for X 27 (S7/M7 (CP 440) – CP 340/CP 341/CP 440/CP 441)
The figure below illustrates the connecting cable for a point-to-point connection
between a CP 440 and a CP 340/CP 341/CP 440/CP 441 for RS 485 operation.
For the connecting cables you require the following male connectors:
At the CP 440 end: 15-pin subminiature D male connector with a screw fixing
at the communication partner: 15-pin sub D male with screw fixing
CP 440
Sender
Receiver
Casing shield
1) In the case of cables longer than 50 m you must solder in a terminating
resistor of approx. 330
Figure B-2
Point-to-point connection CP 440 Installation and Parameter Assignment
A5E00057742-02
2 T(A)–
9 T(B)+
4 R(A)–
1)
11 R(B)+
8 GND
Cable type
LIYCY 3 x 2 x 0.14.
R(A)/R(B) twisted.
on the receiver for trouble-free traffic.
X27 Connecting Cable for CP 440 – CP 340/CP 341/CP 440/CP 441 for
RS 485 Operation (Two-Wire)
Communication partner
T(A)– 2
T(B)+ 9
R(A) 4
1)
R(B) 11
Receiver
GND 8
Shield
Casing shield
Connecting Cables
Sender
B-5