Endress+Hauser PROline promag 23, Operating Instructions Manual

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PROline Promag 23 9 Trouble-shooting
Hauser 69
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 reset 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 current Positive zero return is activated
"
Caution:
System or process errors defined as “Notice messages” have no effect whatsoever on the
inputs and outputs. See the information on Page 45 ff.
Current output MAXIMUM CURRENT
HART 4–20 mA (NAMUR)
o
22 mA
HOLD VALUE
Last valid value (preceding occurrence of the
fault) is output.
ACTUAL VALUE
Fault is ignored, i.e. normal measured-value
output on the basis of ongoing flow measure-
ment.
Output signal corresponds to
“zero flow”
Pulse output FALLBACK VALUE
Signal output
o
no pulses
HOLD VALUE
Last valid value (preceding occurrence of the
fault) is output.
ACTUAL VALUE
Fault is ignored, i.e. normal measured value
output on the basis of ongoing flow measure-
ment.
Output signal corresponds to
“zero flow”
Frequency output FALLBACK VALUE
Signal output
o
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. normal measured value
output on the basis of ongoing flow measure-
ment.
Output signal corresponds to
“zero flow”