Hi there, You can make use of FB41, FB42, FB43, FB58 and FB59 for PID control in STEP7. Check out the links below for some useful resources and tutorials to configure PID control for Siemens PLCs using STEP7.
SIMATIC Standard PID Control Manual: https://sie.ag/2KcjEUo
PID with a Siemens S7-1200 PLC: https://bit.ly/2M3T81g
How to configure PID controller in Siemens PLC?: https://bit.ly/2n06OQc
I hope this helps.