Endress+Hauser Promass 40 - Response of Outputs to Errors

9 Trouble-shooting Promass 40
42 Endress+Hauser
9.5 Response of outputs to errors

Note:
The failsafe mode of totalizers, current, pulse and frequency outputs can be customised
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 inputs and
outputs. See the information on
→ Page 26 ff.
Current output MINIMUM CURRENT
HART 4–20 mA (25 mA)
→ 2 mA
HART 4–20 mA
→ 2 mA
MAXIMUM CURRENT
HART 4–20 mA (25 mA)
→ 25 mA
HART 4–20 mA (NAMUR)
→ 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
→ 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”