Siemens siprotec 7SA6 User Manual page 169

Example 3 (PLC1):
Additional Logic
7SA6 Manual
C53000-G1176-C133-1
Function
Key 4
CB is
CLOSED
CB is
OPEN
GS is
CLOSED
GS is
OPEN
IS is
CLOSED
IS is
OPEN
Door
is CLOSED
Figure 5-43 Interlocking an disconnect switch as an example of a user defined interlock
protective function
By using slow PLC processing, an additional, event-driven logic condition may be
constructed which delivers indications regarding switch-gear operating status. These
indications may be passed externally via LEDs or relay contacts, or used as input
signals for further logical links. In the example (see Figure 5-44), the output
information indication from the circuit breaker interlocking logic (CB TRIP) and a joint
indication from all protective element trip signals (Protection TRIP) are linked to a new
"&LUFXLW %UHDNHU 2SHUDWLRQ" message. Furthermore, the single point indication
(SP) 7HVW 2SHU, which may be coupled via a binary input, is linked with an internal
reusable "7HVW RSHU" message.
CB TRIP
Protection TRIP
>Test Oper.
Additional logic as an example for a PLC_1 event-driven logic condition
Figure 5-44
≥1
≥1
&
=1
≥1
Configuration
Disconnector
Close
Circuit Breaker
Operation
Test Oper.
5-45