Endress+Hauser Prosonic Flow 90, Operating Instructions Manual

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9 Trouble-shooting Proline Prosonic Flow 90
86 Hauser
9.5 Response of outputs to errors
!
Note!
The failsafe mode of totalizers, current, pulse and frequency outputs can be customized by means
of various functions in the function matrix. You will find detailed information on these procedures
in the “Description of Device Functions” manual.
Positive zero return and failsafe mode:
You can use positive zero return to set the signals of the current, pulse and frequency outputs to
their fallback value, for example when measuring has to be interrupted while a pipe is being
cleaned. This function takes priority over all other device functions; Simulations, for example, are
suppressed.
Failsafe mode of outputs and totalizers
Process/system error is present Positive zero return is activated
"
Caution!
System or process errors defined as “Notice messages” have no effect whatsoever on the outputs. See the information on
Page 47 ff.
Current output MINIMUM CURRENT
The current output will be set to the lower value of
the signal on alarm level depending on the setting
selected in the CURRENT SPAN (see the “Descrip-
tion of Device Functions” manual).
MAXIMUM CURRENT
The current output will be set to the higher value of
the signal on alarm level depending on the setting
selected in the CURRENT SPAN (see the “Descrip-
tion of Device Functions” manual).
HOLD VALUE
Measured value display on the basis of the last saved
value preceding occurrence of the fault.
ACTUAL VALUE
Measured value display on the basis of the current
flow measurement. The fault is ignored.
Output signal corresponds to “zero
flow”
Pulse output FALLBACK VALUE
Signal output
→
no pulses
HOLD VALUE
Last valid value (preceding occurrence of the fault)
is output.
ACTUAL VALUE
Fault is ignored, i.e. standard measured value output
on the basis of ongoing flow measurement.
Output signal corresponds to “zero
flow”
Frequency output FALLBACK VALUE
Signal output
→
0 Hz
FAILSAFE LEVEL
Output of the frequency specified in the FAILSAFE
VALUE function.
HOLD VALUE
Last valid value (preceding occurrence of the fault)
is output.
ACTUAL VALUE
Fault is ignored, i.e. standard measured value output
on the basis of ongoing flow measurement.
Output signal corresponds to “zero
flow”