Delta AS Series Programming Manual page 764

Formula of the output cycle:
Set the output cycle according to the environment. If the environmental temperature changes not so aggressively, you
can set a bigger output cycle.

Output pulse width = MV (%) x output cycle
Execute the general pulse with modulation instruction (GPWM) to set Output pulse width and output cycle sampling time
to manage the cycle.
Example
If the output cycle is 2000 ms, then the output value is 50% after the PID algorithm is implemented.

Output pulse width = 50% × 2000 ms = 1000 ms
In other words, the GWPM instruction can be set to Output pulse width = 1000 and output cycle = 2000.
t =10 0 0 ms
Ou tp u t Y 1 0
T =2 00 0 ms
Note
1. When tuning the parameters Kc_Kp, Ti_Ki, and Td_Kd (PID_MODE=0), set the Kc_Kp value first, and then set
the Ti_Ki and Td_Kd values to 0. In a controlled environment, you can increase the values of Ti_Ki (from
smaller to bigger) and Td_Kd (from bigger to smaller). When the value of Kc_Kp is 1, the proportional gain is
100%. That is, the error values increase by a factor of one. When the proportional gain is less than 100%, the
error values decrease. When the proportional gain is greater than 100%, the error values increase.
2. The parameters which have been automatically tuned are not necessarily suitable for every controlled
environment. You can, therefore, further modify the automatically-tuned parameters, but it is recommended
that you only modify the values of Ti_Ki or Td_Kd.
3. The operand CYCLE is to set the sampling time to use the PID algorithm and refresh MV.
4. When the number of the channel for measurement is changed, the time to refresh the measured value also
changes. For example, the measured value is refreshed every 200 ms when there is only 1 channel for
measurement. The measured value is refreshed every 800 ms when there are 4 channels for measurement.
The Kc_Kp, Ti_Ki, Td_Kd parameters may differ when the number of channel for measure is different.
Cha p ter 6 App l ied Ins truc tio ns
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