How do you implement and tune a PID controller in a PLC?

PLC PID implementation: use built-in PID instruction/function block, configure scaling (engineering units to percent), set control action (direct/reverse), configure output limits, enable anti-windup. Tuning procedure: put in manual, perform step test to identify process characteristics (gain, time constant, dead time), apply tuning rules (Ziegler-Nichols, Lambda), fine-tune for desired response. Common issues: incorrect scaling, wrong control action, improper sample time, and integral windup. Most PLCs provide PID faceplates for operator interface with auto/manual, setpoint, and tuning parameters.