Use In Protective Systems; Device Behavior During Operation - Endress+Hauser Proline Prosonic Flow P 500 Functional Safety Manual

Proline Prosonic Flow P 500 HART
5

Use in protective systems

5.1

Device behavior during operation

5.1.1 Device behavior during power-up
Once switched on, the device runs through a start-up phase. The current output is set to
failure current during this time. This current is ≤ 3.6 mA in the initial seconds of this start-up
phase.
No communication with the device is possible via the interfaces during the start-up phase.
After the start-up phase the device switches to the normal mode (measuring operation).
5.1.2 Behavior of device during operation
The device outputs a current value which corresponds to the measured value to be monitored.
This value must be monitored and processed further in an attached automation system.
5.1.3 Device behavior in safety function demand mode
Depending on the setting of the Failure mode parameter, the current is as follows in demand
mode:
• For Min. option: ≤ 3.6 mA
• For Max. option: ≥ 21 mA
5.1.4 Device behavior in event of alarms and warnings
The output current on alarm can be set to a value ≤ 3.6 mA or ≥ 21 mA.
In some cases (e.g. a cable open circuit or faults in the current output itself, where it is not
possible to set the failure current ≥ 21 mA) output currents of ≤ 3.6 mA occur irrespective of
the configured failure current.
In some other cases (e.g. short circuit of cabling), output currents of ≥ 21 mA occur
irrespective of the configured failure current.
For alarm monitoring, the downstream automation system must be able to recognize both
maximum alarms (≥ 21 mA) and minimum alarms (≤ 3.6 mA).
5.1.5 Alarm and warning messages
Additional information is provided by the alarm and warning messages output in the form of
diagnostic events and associated event texts.
NOTICE
A diagnostic message is displayed even though the diagnostic event is no longer active in
the unlocked SIL mode.
When SIL mode is activated, additional diagnostics are activated. If a diagnostic event is
pending and the locked SIL mode is deactivated, the diagnostic message remains as long as
the error is still present.
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In this case, the device must be disconnected briefly from the power supply .
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When the device is then restarted, a self-check is carried out, and the diagnostics event is
reset where applicable.
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Use in protective systems
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