The Multi-Cycle Temperature Controller ATR421 is a Panel Mounted 1/8 Din Process/Temperature Controller that can have up 15 different cycles and each cycle can have up to 45 steps. The ATR421 has a digital input and up to 4 relays, Voltage, current output as well as an option for Modbus RS485. The ATR421 accepts sensor inputs from K, J, S or R type thermocouples, Pt100, Pt500, Pt1000 and Ni100 RTD'S and PTC1K and NTC10K Thermistor inputs. The ATR421 also accepts inputs from sensors with 4-20mA, 0-20mA, or 0-10V outputs. The ATR421 can also accept input from potentiometers. The ATR421 has two 4 digit displays one for the process variable and the other for the set point. The ATR421 is 1/8 Din standard 48 x 96 mm and is able to withstand environmental conditions up to IP65 with the optional gasket. The ATR421 can be programmed with the front panel keypad or PC based software and multiple units can be cloned with the use of a memory card enabling high-speed configuration. The PC based software can also be used to monitor several Temperature Controllers. Desired control is maintained with PID and auto-tuning.