Test Sequence A (Approach The Level) - Endress+Hauser Proserve NMS80 Functional Safety Manual

Use in safety instrumented systems
22
5.3.1

Test sequence A (Approach the level)

Preparatory steps
1. Point level monitoring and range monitoring can also be performed when the SIL
mode is active.
2. If the safety-related "Analog" signal is used, connect a suitable measuring device
(recommended accuracy better than ±0.1 mA) in the installed circuit.
3. If the "Digital" safety-related signal is used, connect a suitable measuring device
(resistance tester/resistance measurement), (recommended accuracy better than
±0.1 Ω) to the digital output.
4. Determine the safety setting (point level or range monitoring).
Procedure for point level monitoring
1. Check safety function: Approach at least one level immediately above (MAX
monitoring) or below (MIN monitoring) the point level to be monitored.
2. Check safety function: Read the output current (mA)/relay resistance value (Ω),
record it and assess for accuracy.
3. If an additional (optional) check of the measuring point function is to be carried out
immediately before the switch point: Check the function before the MIN or MAX
switch point: Approach the level directly below (MAX monitoring) or above (MIN
monitoring) the point level to be monitored. Read the output current/relay resistance
value, record it and assess for accuracy. This does not check the safety function of the
device.
The test has been passed successfully if the current values/relay resistance values trigger
or ensure the required function.
Procedure for range monitoring
1. Approach five levels within the range to be monitored.
2. For every level value, read the output current (mA)/relay resistance value (Ω), record
it and assess for accuracy.
The test has been passed successfully if the current values/relay resistance values in step 2
are within the required level of accuracy.
Relay self-monitoring
Relay self-monitoring must only be performed if the "Digital" safety-related signal is used.
Example of terminal designation: If the Digital IO module used for the safety function is
installed in slot D and contacts 3 and 4 are used, Digital D3-4 must be used instead of
Digital Xy-z below.
E 1
2
1
CDI
i
1 3
F
2 4
G 1
2 HR
on
3
WP
POWER SIM
D
1 2 3 4
C 1 2 3 4 5 6 7 8
B 1 2 3 4 5 6 7 8
A 1 2 3 4
Proserve NMS80
A0032860
Endress+Hauser