Series M1 and M3 controllers are suitable for a wide range of temperature control applications. M1 is a basic controller, while M3 performs Heat/Cool control and provides auxiliary current transformer input. All M1 and M3 controllers include features such as autotune, IP65 front panel protection, serial communications, analog output signal for retransmission, custom linearization, transmitter power supply, start-up and timer functions. They are compact “1/16 DIN”-sized.