Response Of Outputs To Errors - Endress+Hauser Proline Prosonic Flow 91 Operating Instructions Manual

Troubleshooting
!
Failsafe mode of outputs and totalizers
Process/system error is present
Current output MINIMUM VALUE
4–20 mA (25 mA) → 2 mA
4–20 mA NAMUR → 3.5 mA
4–20 mA US → 3.75 mA
4–20 mA (25 mA) HART → 2 mA
4–20 mA HART NAMUR → 3.5 mA
4–20 mA HART US → 3.75 mA
MAXIMUM VALUE
4–20 mA (25 mA) → 25mA
4–20 mA NAMUR → 22.6 mA
4–20 mA US → 22.6 mA
4–20 mA (25 mA) HART → 25 mA
4–20 mA HART NAMUR → 22.6 mA
4–20 mA HART US → 22.6 mA
ACTUAL VALUE
Fault is ignored, i.e. standard measured value output on the basis of ongoing flow
measurement (not recommended).
MINIMUM/MAXIMUM VALUE → FALLBACK VALUE
Pulse output
Signal output → No pulses
ACTUAL VALUE
Fault is ignored, i.e. standard measured value output on the basis of ongoing flow
measurement.
MINIMUM/MAXIMUM VALUE → STOP
Totalizer
The totalizer is paused until the fault is rectified.
ACTUAL VALUE
The fault is ignored. The totalizer continues to count in accordance with the current flow
value.
In the event of fault or power supply failure: status output → Non-conductive
Status output
54
9.4

Response of outputs to errors

Note!
The response of the totalizer, current output, pulse output and status output is defined in the
FAILSAFE MODE function (→ ä 99).
The outputs can be set to their fallback value be means of the postitive zero return. Applicable when
operation has to be interrupted while a pipe is being cleaned. This function takes priority over all
other device functions; simulations, for example, are suppressed.
Proline Prosonic Flow 91
Positive zero return is activated
Output signal corresponds to "zero flow"
Output signal corresponds to "zero flow"
Totalizer stops
No effect on status output
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