Manual 36526A
DPG-21XX-00X Digital Controllers
Woodward
38
TROUBLESHOOTING TABLE (Cont’d.)
SYMPTOM
REMEDY
Engine Does Not Reach
Set Speed
Improve PID tuning.
Integral too low or zero
PID values are too low. A tuning that is too soft can prevent
the controller from delivering the needed actuator drive signal
to reach the set speed.
PID values are too high. Tuning is too hot or oversensitive to
small speed errors, which causes the controller to make large,
rapid changes in actuator drive signal, creating an average
signal that is inadequate.
The Integral Low Limit setting is too high. Return the value to
the default setting of zero.
The Integral High Limit setting is too low. Return the value to
the default setting of 99.
Engine Takes Too Long to
Reach the Set Speed
Improve PID tuning.
Integral setting is too low.
Startup Rate setting is too low.
Accel Rate setting is too low.
Speed Filter setting is too high.
Engine Does Not Track Speed
Setting Changes
Is the LED blinking fast (3 Hz)? No = not sensing speed.
Is the selected set speed parameter being modified?
A PID value or a Gain value is too high.
A PID value is too low or zero.
Accel Rate is set too low.
Decel Rate is set too low.
Sluggish Response to
Load Changes
Gain too low.
Improve PID tuning.
Speed filter setting is too high.
Engine Instability With
No Load
Improve PID tuning.
Speed filter setting is too low.
Fuel is restricted. Check actuator linkage.
Battery voltage is too low.
Engine Instability With Load
Improve PID tuning.
Fuel is restricted. Check actuator linkage.
Battery voltage is too low.
Engine Unable to Carry
Rated Load
PID values may be too high, causing the controller to
overreact and make large, rapid changes in PWM duty cycle
output to the actuator.
Improve PID tuning.
Fuel is restricted. Check actuator linkage.
