KROHNE OPTISWITCH 3300C NAMUR EN - Manual (Page 22)

Note:
The mode on the NAMUR amplifier must be set so that the
switching output goes to safe condition in case a fault
message is received (I <=1 mA).
Level Signal current -
Sensor
Control lamp
Falling characteris-
tics max.
>=2.2 mA
Falling characteris-
tics max.
<=1.0 mA
Rising characteris-
tics min.
>=2.2 mA
Rising characteris-
tics min.
<=1.0 mA
Failure any <=1.0 mA
flashes
6.4 Recurring function test
According to IEC 61508.
OPTISWITCH 3300 C 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:
OPTISWITCH 3300 C
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 OPTISWITCH 3300 C - with NAMUR output
Set up
31358
-EN
-060830