Siemens SIPROTEC 4 7UT6 Series Manual page 350

Mounting and Commissioning
3.2 Checking Connections
•
RTS = Request to send
•
CTS = Clear to send
•
GND = Signal/Chassis Ground
The cable shield is to be grounded at both ends. For extremely EMC-prone environments, the GND may be
connected via a separate individually shielded wire pair to improve immunity to interference.
The following table lists the assignments of the DSUB port for the various serial interfaces.
Table 3-26
Pin-No. RS232
1
2 RxD
3 TxD
4 –
5 GND
6 –
7 RTS
8 CTS
9 –
1) Pin 7 also carries the RTS signal with RS232 level when operated as RS485 interface. Pin 7 must therefore not be
connected!
Termination
The RS485 interfaces are capable of half-duplex service with the signals A/A' and B/B' with a common reference
potential C/C' (GND). It must be checked that the terminating resistors are connected only for the respectively
last device of the bus but not for all other devices of the bus.
The jumpers for the terminating resistors are located on the interface module RS485 (see
PROFIBUS RS485 (see
It is also possible that the terminating resistors are arranged externally
If the bus is extended, verify again that only the last device on the bus has the terminating resistors
connected, and that the other devices on the bus do not.
Time Synchronisation Interface
Either DC 5 V, DC 12 V or DC 24 V time synchronisation signals can be processed if the connections are made
as indicated in the table below.
Table 3-27
Pin No. Designation
1 P24_TSIG
2 P5_TSIG
3 M_TSIG
4 M_TYNC
1)
5 SCREEN
6 –
7 P12_TSIG
350
Assignment of the connectors for the various serial interfaces
RS485 Profibus FMS Slave, RS485
Profibus DP Slave, RS485
Shield (with shield ends electrically connected)
–
A/A' (RxD/TxD-N)
–
C/C' (GND)
– +5 V (belastbar mit <100 mA)
– 1)
B/B' (RxD/TxD-P)
–
Figure 3-18).
D-subminiature connector assignment of the time synchronisation interface
–
B/B' (RxD/TxD-P)
CNTR-A (TTL)
C/C' (GND)
–
A/A' (RxD/TxD-N)
–
Signal significance
Input 24 V
Input 5 V
Return line
Return line 1)
Screen potential
–
Input 12 V
Modbus RS485 Ethernet
DNP3.0 RS485 EN 100
–
A
RTS (TTL Pegel)
GND1
VCC1
–
B
–
existent
Figure 3-17) or
(Figure 3-19).
SIPROTEC 4, 7UT6x, Manual
C53000-G1176-C230-5, Edition 09.2016
Tx+
Tx–
Rx+
—
—
Rx–
—
—
non