Emerson PACMotion VFD Series User Manual page 62

Par Parameter Name
P3-11 PID error limit to enable ramps
Defines a threshold PID error level, whereby if the difference between the setpoint and feedback values
is less than the set threshold, the internal ramp times of the drive are disabled. Where a greater PID error
exists, the ramp times are enabled to limit the rate of change of motor speed on large PID errors, and react
quickly to small errors.
Setting to 0.0 means that the drive ramps are always enabled. This parameter is intended to allow the user
to disable the drive internal ramps where a fast reaction to the PID control is required, however by only
disabling the ramps when a small PID error exists, the risk of possible over current or over voltage trips
being generated are reduced.
P3-12 PID feedback display scaling
Applies a scaling factor to the displayed PID feedback, allowing the user to display the actual signal level
from a transducer, e.g. 0 – 10 Bar etc.
P3-13 PID wakeup error level
Sets a programmable level whereby if the drive enters standby motor whilst operating under PID
control, the selected feedback signal must fall below this threshold before the drive will return to normal
operation.
P3-18 PID reset control
0 Continuous operation
1 Operate only when the
drive is enabled
62
In this operating mode, the PID controller operates continuously,
regardless of whether the drive is enabled or disabled. This can result
in the output of the PID controller reaching the maximum level prior to
the drive enable signal being applied.
In this operating mode, the PID controller only operates when the drive
is enabled, and hence will always start from zero when the drive is
enabled.
PACMotion VFD AC Variable Speed Drive User Guide
Minimum Maximum Default
0.0 25.0
0.000 50.000
0.0 100.0
0 1
Units
0.0 %
0.000 -
5.0 %
1 -
GFK-3111A