PID Temperature Controller Allen Bradley 1771-TCM Brian Van Eyk

Background Applications Plastic injection molding Powder paint There is a need for quick and accurate temperature control Two solutions Sensor with simple logic controller Smart I/O controller

Allen Bradley 1771-TCM Uses PID controller 8 independent control loops Heating or cooling control Auto-Tuning software Speeds up design Accurate gains Analog or digital control Standard PLC-5 rack mount

Control Loops Thermocouples used for feedback Open loop detection Disable unit or output constant value Data collected in the TCM is given to the PLC PLC controls actuator

PID Auto-Tuning Auto-Tune calculates PID gains Gains are stored in TCM module Gains must be read into PLC data table TCM can be set to slow, medium or fast response time TCM memory is volatile TCM must have gains sent to it or auto-tune whenever power to the module is lost

PID Fine-Tuning Fine tuning can be done manually Too much overshoot Decrease P and I Increase D Too slow Increase P and I Decrease D

Analog vs. Digital Control TCM module has two possible outputs: Analog control allows PLC to set the temperature of the heating / cooling device Digital control gives the PLC the duty cycle for the actuator

Alarms Alarms can be set Alarm is sent to the PLC High and low temperature alarm values High and low deviations Can use with dead band or without Alarm is sent to the PLC The PLC programmer can do what they want with the alarm

Mounting Termination panel mounted separately Standard DIN style Mount in panel near thermocouples Two cables from termination panel to TCM Provides more accurate temperature readings

Questions Cost - $3,150