VEGA VEGAVIB 66 - NAMUR - Manual (Page 22)

Note:
The mode adjustment on the NAMUR amplifier must be
selected in such a way that the switching output goes to safe
position in case of a failure message (I <=1 mA).
Level Signal current -
Sensor
Control lamp
Falling characteris-
tics max.
>=2.2 mA
Falling characteris-
tics max.
<= 1 mA
Rising characteris-
tics min.
>=2.2 mA
Rising characteris-
tics min.
<= 1 mA
Failure any <= 1 mA
flashes
6.4 Recurring function test
According to IEC 61508.
VEGAVIB 66 is qualified in mode A (overfill protection) for use
in measuring chains of stage SIL2 according to IEC 61508
(redundant, stage SIL3).
The following instrument combinations meet the requirements
according to SIL:
VEGAVIB 66
l Oscillator VBE60N
The recurring test according to IEC 61508 can be carried out
by pushing the simulation key on the oscillator or by briefly (>2
seconds) interrupting the cable to the sensor. The correct
SIL
Recurring function test
22 VEGAVIB 66 - with NAMUR output
Set up
31219
-EN
-060508