PID control This section contains information on the following topics:PID basic functions (S7-300, S7-400)PID Self Tuner (S7-300, S7-400)Standard PID Control (S7-300, S7-400)Modular PID Control (S7-300, S7-400)FM 355 PID Control (S7-300, S7-400)FM 355-2 Temperature Control (S7-300, S7-400)FM 455 PID Control (S7-300, S7-400)