Xinje XD Series User Manual page 290

7-7．Application
Example 1:
PID control program is shown below:
SM0
M1
M2
M0
M1
M2
M2
HD2.8 HD09 K0
HD2.8 HD09 K1
Soft element function comments:
HD2.7: Auto tune bit
HD2.8: Successful flag of auto tune
M0: Normal PID control
M1: Auto tune control
M2: Enter PID control after auto tune
Operation steps:
1. Send the actual temperature to PID collection register
2. Set probably value for P, I, D, sampling period
3. Set ON auto tune control bit M1 to startup PID auto tune
4. M1 will be reset after the auto tune is finished
5. Set ON M0, use the PID parameters getting from auto tune
6. If the PID effect is not good by using the auto tune PID parameters, user can adjust the PID
parameters to get good effect.
Note: This PLC temperature PID control program is applicable to almost all temperature
control projects.
MOV ID100 D10
HD2.7
( S )
PID D0 D10 HD0 Y0
HD2.7
( R )
M1
( R )
289
// Move ID100 content into D10
// auto tune mode, or set to autotune mode
after auto tune end
// start PID, D0 is target value, D10 is the
measured value, from HD0 is PID
parameters area; output PID result byY0
// PID control finish, close auto tune PID
mode
// if auto tune is successful, and overshoot is
permitted, close auto tune control bit, auto
tune will finish;
If auto tune turns to be manual mode, and
overshoot is not permitted, close auto
tune control bit.