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the profile at its current state. The action of Holdback is the same as a deviation alarm. It
can be enabled or disabled. Holdback has three parameters.
Holdback wait time
Holdback band
Holdback type.
If the error from the set point exceeds the set holdback band (Band), then if the
holdback feature is enabled it will automatically freeze the profile at its current point. At the
same time, the holdback timer begins to count. When the value of holdback timer exceeds
the value of holdback wait time (wait time), the profiler will no longer be freeze and jump to
its next segment, at the same time an error code HBER will be displayed. If the error
comes within the holdback band (Band), then the program will resume normal running.
Hold Back Types:
There are four different Holdback types. The choice of type is made by setting
Holdback parameter when creating a profile with any one of the following
OFF-Disables Holdback - no action is taken.
Deviation Lo-Deviation Low Holdback holds the profile back when the process
value deviates below the set point by more than the holdback band (Band).
Deviation High-Deviation high holdback holds the profile back when the process
value deviates above the set point by more than the holdback band (Band).
Deviation Lo/High -Deviation Lo/High Holdback is a combination of the two. It
holds the profile back when the process value deviates either above or below the
set point by more than the holdback band (Band).
Hold Back Action:
Holdback action is defined by the below parameters.
Wait Forever
Wait Time
If wait forever is enabled then process will wait until the PV is come within
Holdback band (Band). If wait forever is disabled then the holdback action specified
in Action after a timeout will be finished after the time specified in wait time. The
available holdback actions are Hold and Continue. Hold will hold the segment and
the continue will move to the next segment.
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