11
When set to the window function the upper limit value [FH] and the lower
limit value [FL] are defined. The distance between FH and FL is at least 4
% of the final value of the measuring range. FH and FL have a fixed
hysteresis of 0.25 % of the final value of the measuring range. This keeps
the switching status of the output stable if the flow rate varies slightly.
5.6 Analogue output
The unit provides an analogue signal of 4…20 mA proportional to the process
value.
The measuring range is scalable:
• [ASP] determines at which measured value the output signal is 4 mA.
• [AEP] determines at which measured value the output signal is 20 mA.
Minimum distance between ASP and AEP = 20 % of the final value of the
measuring range.
For flow measurement in the operating mode REL, ASP and AEP are not
available. In this operating mode, the characteristic curve of the analogue
output is defined by the flow adjustment: high flow = 20 mA; low flow = 4
mA.
If the measured value is outside the measuring range or in the event of an internal
error, the current signal indicated in the following figure is provided.
For measured values outside the display range or in case of a fault, messages are
displayed (UL, OL, Err).
The analogue signal in case of an error is adjustable
35):
• [FOU] = On: In case of a fault the analogue signal goes to the upper end stop
value (22 mA).
• [FOU] = OFF: In case of a fault the analogue signal goes to the lower end stop
value (3.5 mA).
• [FOU] = OU: The analogue signal still corresponds to the measured value.
GB
