Siemens SIPROTEC 7VU681, User Manual

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Mounting And Commissioning
3.2 Checking Connection
SIPROTEC, 7VU681, User Manual
C53000-G1176-C368-1, Release Date 07.2012
78
• TxD = Data Output
• RxD = Data Input
• 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-loaded environments the GND may be
integrated into a separate individually shielded wire pair to improve the immunity to interference.
Table 3-17 The assignments of the D-subminiature and RJ45 connector for the various interfaces
1)
Pin 7 also carries the RTS signal with RS232 level when operated as RS485 Interface. Pin 7 may therefore
not be connected!
3.2.3 Termination
The RS485 interface is capable of half-duplex service with the signals A/A' and B/B' with a common relative
potential C/C' (GND). Verify that only the last device on the bus has the terminating resistors connected, and
that the other devices on the bus do not. The jumpers for the terminating resistors are located on the interface
module RS485 (see Figure 3-9) or on the PROFIBUS module RS485 (see Figure 3-10). The terminating
resistors can also be connected externally. In this case, the terminating resistors located on the module must
be disabled.
If the bus is extended, make sure again that only the last device on the bus has the terminating resistors
switched-in, and that all other devices on the bus do not.
3.2.4 Time Synchronization Interface
Either 5 VDC, 12 VDC or 24 VDC time synchronization signals can be processed if the connections are made
as indicated in the table below.
Pin
No. RS232 RS 485 Profibus DP Slave,
RS 485
Modbus, RS485 Ethernet
EN100
Redundant T103
1 Shield (with shield ends electrically connected) Tx+ B/B’ (RxD/TxD-P)
2 RxD – – – Tx- A/A’ (RxD/TxD-N)
3 TxD A/A’ (RxD/TxD-N) B/B’ (RxD/TxD-P) A Rx+
4 – – CNTRA-(TTL) RTS (TTL level) –
5 EARTH C/C' (EARTH) C/C' (EARTH) EARTH1 –
6 – – +5 V (max. load < 100
mA)
VCC1 Rx-
7 RTS –
1)
– – –
8 CTS B/B’ (RxD/TxD-P) A/A’ (RxD/TxD-N) B –
9 – – – – Disabled