Tolerance Window For Two-Channel Evaluation; Figure 13: Tolerance Window And Discrepancy Mode - Maximum Unit Value - WAGO 753-668/000-004 Manual

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753-668/000-004 4FAI 0/4-20 mA Diff PROFIsafe
4.6

Tolerance Window for Two-Channel Evaluation

Two-channel use of the analog inputs checks whether the input measured values
of both channels of a channel pair differ from one another. A tolerance window
can be defined within which the input measured values may deviate from one
another.
There are three possible settings for the tolerance window:
•
Relative: Relative parameter values are set in %, which refer to the
process value (unit value 1, see Section "Definition of the Unit Value"). The
smaller the parameter value, the smaller the tolerance window. The larger
the parameter value, the larger the tolerance window.
•
Absolute: Absolute values dependent on the measuring range are set in
%.
•
Relative + absolute: With this setting, the larger of the two tolerance
windows is determined dynamically (at runtime). In the lower tolerance
range, the absolute tolerance dominates, while the relative tolerance
dominates in the upper measuring range. Overall, with this setting, a larger
tolerance window is available.
As soon as a channel pair leaves the defined tolerance window, it is in
discrepancy mode, see Section "Functions" > ... > "Discrepancy Time".
Figure 13: Tolerance Window and Discrepancy Mode – Maximum Unit Value
Version 1.0.0, valid from HW/SW Version 01/01
Functions 55
Manual