The Model GMPID series modules are full featured PID controllers designed for use with the Graphite® products. The GMP1 is a single loop controller, while the GMP2 is a dual loop controller. The design of the system provides a true modular PID control platform for multi-zone control applications. The modules can accept a wide range of thermocouple, RTD, 0-10 V, 0/4-20 mA signals. With multiple discrete outputs, plus an optional analogue output (GMP1 only), the GMPID modules can perform virtually any combination of time-proportioning or linear control for heat, cool, or heat/cool applications. The discrete outputs may also be assigned to one of seven internal soft alarms. The GMP1’s optional linear output can be assigned to transmit virtually any internal variable. The modules connect and Communicate via proprietary USB connection to the various Graphite host devices. The Graphite host devices, equipped with serial ports as well as an Ethernet port(s), allows the system to share data with PCs, PLCs and SCADA systems. The maximum number of modules various for each Graphite host device, see specific models for details. Once programmed, the module will continue to operate/control independent of the Graphite host device as long as power is applied. Remove power from the host device before installing or replacing any modules. The GMPID modules are available with various discrete output combinations, including relays and open drain MOSFETs. For applications requiring large loads to be controlled, several DIN rail mount relays are available. The modules can operate in On/Off, P, PI, or PID control mode and use an on-demand Auto-Tune that establishes the tuning constants. The PID constants may be fine-tuned through the serial or Ethernet interface. The modules employ a unique overshoot suppression feature, which allows the quickest response without excessive overshoot. The modules can also be operated in manual mode, providing the operator with direct control of the output.