Connector Pin Assignments - Siemens SIMATIC S7-200 System Manual

Connector Pin Assignments

The communications ports on the S7-200 CPU are RS-485 compatible on a nine-pin subminiature
D connector in accordance with the PROFIBUS standard as defined in the European Standard
EN 50170. Table 7-7 shows the connector that provides the physical connection for the
communications port and describes the communications port pin assignments.
Table 7-7 Pin Assignments for the S7-200 Communications Port
Connector
Pin 1
Pin 6 Pin 6
Pin 9 Pin 9
Pin 5
Biasing and Terminating the Network Cable
Siemens provides two types of network connectors that you can use to easily connect multiple
devices to a network: a standard network connector (see Table 7-7 for the pin assignments), and
a connector that includes a programming port, which allows you to connect a programming station
or an HMI device to the network without disturbing any existing network connections. The
programming port connector passes all signals (including the power pins) from the S7-200
through to the programming port, which is especially useful for connecting devices that draw
power from the S7-200 (such as a TD 200).
Both connectors have two sets of terminal screws to allow you to attach the incoming and
outgoing network cables. Both connectors also have switches to bias and terminate the network
selectively. Figure 7-22 shows typical biasing and termination for the cable connectors.
Cable must be terminated
and biased at both ends.
Bare shielding: approximately 12 mm (1/2 in.) must contact the metal guides of all locations.
Switch position = On:
Terminated and biased
390 Ω
B
TxD/RxD +
A 220 Ω
TxD/RxD -
390 Ω
Cable shield
Figure 7-22 Bias and Termination of the Network Cable
Pin Number PROFIBUS Signal
1 Shield
2 24 V Return
3 RS-485 Signal B
4 Request-to-Send
5 5 V Return
6 +5 V
7 +24 V
8 RS-485 Signal A
9 Not applicable
Connector shell Shield
Switch position = On Switch position = Off
Terminated and biased No termination or bias
On
A B A B
Switch position = Off:
No termination or bias
Pin #
6
3
Network
connector
8
5
1
Communicating over a Network
Port 0/Port 1
Chassis ground
Logic common
RS-485 Signal B
RTS (TTL)
Logic common
+5 V, 100 Ω series resistor
+24 V
RS-485 Signal A
10-bit protocol select (input)
Chassis ground
Switch position = On
Terminated and biased
Off
A B A B A B A B
TxD/RxD +
TxD/RxD -
Cable shield
TxD/RxD +
TxD/RxD -
Cable shield
Chapter 7
On
B
Pin #
A
6
B
3
A
8
5
1
223