9-2
Example 1:
Example 2:
Gain = 1.0
Gain = 2.0
Set-Point = 80%
Set-Point = 80%
Feedback = 78%
Feedback = 78%
Error = Set-point - Feedback = 2%
Error = Set-point - Feedback = 2%
Control Error = Gain x Error = 2%
Control Error = Gain x Error = 4%
Please note that an excessive gain can make the system unstable and oscillation may occur.
The response time of the system can be adjusted with the Integral Gain set by parameter 10-06. Increasing the
Integral Time will make the system less responsive and decreasing the Integral Gain Time will increase response
but may result in instability of the total system.
Slowing the system down too much may be unsatisfactory for the process. The end result is that these two
parameters in conjunction with the acceleration (00-14) and deceleration (00-15) times are adjusted to achieve
optimum performance for a particular application.
For typical fan and pump applications a Proportional Gain (10-05) of 2.0 and an Integral Time (10-06) of 5.0
sec. is recommended.
10-03 PID control mode
PID control can be enabled by setting parameter 00-05 to 6 and parameter 10-03 to a value greater than 0.
10- 03
PID Mode Selection
Range
【
0
】
:PID Function disabled
【
1
】
:FWD Characteristic.
Deviation is D-controlled
【
2
】
:FWD Characteristic.
Feedback is D-controlled
【
3
】
:REV Characteristic.
Deviation is D-controlled
【
4
】
:REV Characteristic.
Feedback is D-controlled
