Siemens SICAM P 7KG7750 - Assignment of the Interface

1
1.6 Interface and Terminals
25Power Meter SICAM P 7KG7750/55, Manual
E50417-B1076-C340-A6, Edition 09.2013
1.6.3 Assignment of the Interface
Table 1-3 Terminal assignment of RS485 interface
The housing of the RS485 interface is connected to the protective ground. We recommend using
standard connecting cables. The bus termination is accomplished via the connecting cable.
The isolated supply voltage of the interface is available at the D-Sub female connector, thus
allowing the data signal terminating resistors to be connected to the connecting cable.
Fig. 1-8 Termination of the RS485 interface (external)
Pin No.
RS485 Interface
Modbus / IEC 60870-5-103
Profibus DP
1 Shield Shield
2
3 A B(RxD/TxD-P)
4
5GND
EXT
GND
EXT
6+5 V
EXT
+5 V
EXT
7 RTS CTRL-A
8 B A(RxD/TxD-N)
9
+5 V
390 Ω
220 Ω
390 Ω
B
A
Note
All computing devices connected to the RS485 interface port shall be connected to a SELV (Sep-
arated Extra Low Voltage) circuit and must comply with the following standard: IEC/EN 60950.