hi hieutran8969,

what is maximum PID control?

S7-1500 supports following PID-functions:

please descibe what you want to do more specific.

regards,

Hello hieutran8969,

its ependign which CPU at the 1500 do you want to use.

There are more parameters like cycle time, Integration time and more.
Important is how short is your cycle time of your PID versus your cycle time of your OB1-program.

e.g.

Your cycle time is 10 ms and your cycle time of your PID is 200 ms.
When 1 PID need lower than 0.1 ms per cycle then you call 10 PID-controller.
Then is your cycle time is only between 10 and 11 ms. 

regards
CaOd