The compact controllers of MICROSYST MS8131, are designed for measuring and control of different process parameters. MS8122 is being produced in two basic modifications – MS8131A is with three digital outputs and MS8131B is with two digital and one analogue outputs. The controller can realize positional or proportional control (program selectable). The parameters (proportional band, hysteresis, alarm levels, etc.) are user programmable. The outputs are controlled respectively by logic ON/OFF or by pulse width modulation (PWM). Logically the controllers of the series MS8131 are constructed with one analogue input and 2 independent control channels, each of them with its own set-point and parameters, determining its operating mode, and each of the channels can operate with logic “heating” or “cooling”. This inner organization allows realization of ON/OFF, two-, three-staged, proportional and staged control.