Delta AS Series Programming Manual page 494

Ch ap te r 6 Ap pl ie d Instruc ti ons
Example 4: Creating a DPIDE instruction in a function block and setting to the cyclic task mode to read the function
block written with a DPIDE instruction to control the temperature.
1. Set the value in DPIDE_CYCLE to 1000 ms, and execute the DPIDE instruction by reading the function block written
with a DPIDE instruction. Whenever the function block is scanned, the PID algorithm is applied according to the sampling
time (Cycle), and it refreshes the output value (DPIDE_MV).
2. Set the DPIDE_MODE =1 for auto tuning the parameters for the
temperature control. After tuning is done, the
system is in auto control mode (PID_MODE is set to 0) and fill in the appropriate parameters (Kc_Kp, Ti_Ki, Td_Kd, and
Tf).
3. Main program (cyclic task): Since PLC only executes the DPIDE instruction when it is scanned. If we use TMRH to
work with the DPIDE instruction, for example, set the TMRH to 1000 ms, the system calls the function block written with
a DPIDE instruction (AS_DPIDE) every 1000 ms. See the example program below.
6_
4. Function block (AS_DPIDE): Execute the DPIDE instruction by reading the function block written with a DPIDE
instruction. Whenever the function block is scanned, the PID algorithm is applied according to the sampling time (Cycle),
and it refreshes the output value (DPIDE_MV). (Refer to ISPSoft Manual for more details on how to create a function
block.)
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