Specifications

NOTE: Differential gain is used as a “shock-absorber” to dampen overshoots in fast-acting

systems. However, it can be very sensitive to “noise” on the feedback signal and to

digitizing errors, so it must be used with caution.

80 PID ACC (PID ACCEL/DECEL)

This parameter sets the acceleration and deceleration rate of the setpoint reference into the

PID unit. When the setpoint changes, this function will “filter” the input to the PID unit by

ramping the setpoint reference from the previous value to the new value. This will help

prevent overshoots that can occur when the PID control attempts to respond to step changes

in setpoint, resulting in smoother operation. If PID ACC is set to 0.0 seconds, it is

effectively disabled.

81 MIN ALRM (PID MINIMUM ALARM)

This parameter setting represents the value that the feedback signal (in PID mode) or speed

reference signal (in open-loop speed mode) must fall below to activate the MIN/MAX

ALARM output (see Parameters 52, 53, and 54).

82 MAX ALRM (PID MAXIMUM ALARM)

This parameter setting represents the value that the feedback signal (in PID mode) or speed

reference signal (in open-loop speed mode) must exceed to activate the MIN/MAX ALARM

output (see Parameters 52, 53, and 54).

NOTE: The MIN ALARM function can be used to start and stop the drive based on the

level of the speed reference signal or PID feedback signal. This is done by wiring a 2-wire

start/stop circuit through the drive's Form C relay or open-collector output, and setting the

Form C relay or open-collector output for MIN/MAX (see Parameters 52, 53, and 54).

When the signal drops below the MIN ALARM setting, the relay or open-collector output

will de-energize, which opens the start contact and stops the drive. When the signal is equal

to or greater than the MIN ALARM setting, the relay or open-collector output will energize,

which closes the start contact and starts the drive. The drive must be in REMOTE mode to

use the MIN/MAX function to start and stop the drive.