Allen-Bradley 1404-M4, User Manual

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Publication 1404-UM001D-EN-E - October 2004
Setpoint Programming and Operation 5-3
Over Reverse Setpoint
An over reverse setpoint is the mirror image of an over forward
setpoint. For reverse setpoints, all the magnitudes and limits are
negative.
An over reverse setpoint activates when the magnitude of the
parameter being monitored (defined by the
Setpoint Type ) increases
beyond the Setpoint High Limit in the negative direction and remains
over the limit for a time greater than the Setpoint Action Delay . The
setpoint releases when the magnitude of the parameter being
monitored decreases below the
Setpoint Low Limit and stays below
the limit for a time greater than the Setpoint Release Delay .
Figure 5.2 Over Reverse Setpoint Operation
Under Forward Setpoint
An under forward setpoint is similar to an over forward setpoint,
except the Setpoint High Limit and the Setpoint Low Limit are reversed.
An under forward setpoint activates when the magnitude of the
parameter being monitored (defined by the
Setpoint Type ) decreases
below the Setpoint Low Limit and remains below the limit for a time
greater than the Setpoint Action Delay . The setpoint releases when the
magnitude of the parameter being monitored increases above the
Setpoint High Limit and stays above the limit for a time greater than
the Setpoint Release Delay .
Parameter Value (-)
Setpoint High Limit
Setpoint Low Limit
Setpoint Activated
<Setpoint Action Delay
≥
Setpoint Action Delay
<Setpoint
Release Delay
≥
Setpoint
Release Delay
Time (s)
0
Setpoint Deactivated
Maximum Excursion
Allen-Bradley HMIs