Response Of Outputs To Errors - Endress+Hauser Proline Prosonic Flow 93 PROFIBUS DP/PA Operating Instructions Manual

Troubleshooting
!
Failsafe mode of outputs
Process/system error present
"
Caution!
System or process errors defined as "Notice messages" have no effect whatsoever on the outputs. See the information on → Page 81 ff.
Current output MIN. CURRENT
Depending on the option selected in the CURRENT SPAN function (see "Description of
Device Functions" manual), the current output is set to the value of the lower signal on
alarm level.
MAX. CURRENT
Depending on the option selected in the CURRENT SPAN function (see "Description of
Device Functions" manual), the current output is set to the value of the upper signal on
alarm level.
HOLD VALUE
Measured value displayed is based on the last measured value saved before the error
occurred.
ACTUAL VALUE
Measured value displayed is based on the current flow measurement. The fault is ignored.
Pulse output FALLBACK VALUE
Signal output → No pulses
HOLD VALUE
The last valid measured value (before the error occurred) is output.
ACTUAL VALUE
The fault is ignored, i.e. the measured value is output as normal on the basis of the current
flow measurement.
Frequency output FALLBACK VALUE
Signal output → 0 Hz
FAILSAFE LEVEL
Output of the frequency specified in the FAILSAFE VALUE function.
HOLD VALUE
The last valid measured value (before the error occurred) is output.
ACTUAL VALUE
The fault is ignored, i.e. the measured value is output as normal on the basis of the current
flow measurement.
In the event of a fault or power supply failure: Relay → deenergized
Relay output
The "Description of Device Functions" manual contains detailed information on relay
switching response for various configurations such as error message, flow direction, limit
value, etc.
→ ä 137
PROFIBUS
144
9.5

Response of outputs to errors

Note!
The failsafe mode of the current, pulse and frequency outputs can be customized by means of
various functions in the function matrix. More detailed information on this is provided in the
"Description of Device Functions" manual.
You can use positive zero return to reset the signals of the current, pulse and frequency outputs to
their fallback value, or reset measured value transmission via fieldbus to "0", for example when
measuring has to be interrupted while a pipe is being cleaned. This function takes priority over all
other device functions. This function has priority over all other device functions; simulations are
suppressed, for example.
Proline Prosonic Flow 93 PROFIBUS DP/PA
Positive zero return activated
Output signal corresponds to "zero flow".
Output signal corresponds to "zero flow".
Output signal corresponds to "zero flow".
No effect on the relay output
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Endress+Hauser