VEGA VEGASWING 66 - two-wire With SIL qualification - Manual (Page 25)

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6 Setup
VEGASWING 66 • - two-wire
44952-EN-130805
High coverage (detected errors)
This test is valid if you cannot change the vessel filling or cannot
dismount the sensor.
This function test can be carried out with measurement setups in
conjunction with the two-wire electronics module.
The recurring function test according to IEC 61508 can be carried
out through a short interruption (> 2 seconds) of the supply line to the
sensor. This starts a test sequence.
By doing so, a test procedure is started. The correctness of the sub-
sequent switching conditions on the indications of the SPLC must be
monitored.
a. Short interruption of the supply line to the sensor
You can carry out the function test with the outputted current values
also directly via a safety PLC or a process control system.
1. Separate the instrument briefly (>2 s) from voltage supply.
Check if all three switching conditions change in the correct
sequence and the specified duration. By doing so, you can check
the function of the measuring system.
You can find the test procedure under "Implementation - Function
test".
Make sure the connected downstream devices are activated dur-
ing the function test.
2. Set the mode switch (min./max.)
Check if the switching status changes (signal lamp - switching
status). By doing so, you can check the function of the measuring
system.
If this is not the case, then there is a fault in the measuring sys-
tem.
Make sure the connected downstream devices are activated dur-
ing the function test.
b. Pushing the test key
An integrated test key is lowered in the front plate of the signal con-
ditioning instrument of in the electronics module of the VEGASWING
66. Push the test key for > 2 seconds with a suitable object.
1. Push the test key.
Check if all three switching conditions change in the correct
sequence and the specified duration. By doing so, you can check
the function of the measuring system.
You can find the test procedure under "Implementation - Function
test".
Make sure the connected downstream devices are activated dur-
ing the function test.
2. Set the mode switch (min./max.)
1 Short interruption of the
supply line to the sensor