Chapter 7 Usage of Various Functions
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(4) parameter setting and explanation
(a) PID8 instruction parameter setting and explanation.
① Scan time
Scan time is the period of reading data (sampling), and also 10 times scaled up. The range of sampling time is
0.1 ~ 10 seconds, and actual input range is 0 ~ 100. Generally, Scan time of Digital PID control should be less
than 1/10 of time constant of system response for better performance. Time constant is the time taken the
system’s step response reaches to the 63% of steady state.
② Operation mode
Select automatic or manual operating mode
③ Manual operate range
When manual operation is designates , manual operation value designates.(input range : 0 ~ 4000)
④ Output limit value
Designate minimum and maximum values of available manipulate value.(range : 0 ~ 4000)
⑤ High frequency noise removal ratio
high frequency noise removal ratio is used for derivative control operation, and shows the ratio of high
frequency noise depression. If there is a lot of high frequency noise in the control system, select the value as
higher value.
Otherwise, leave the 1. The range of parameter is 0 ~ 10 and it is not scaled up, so input the designated value
directly.(it is possible that parameter value designates ‘D’ area also)
.