Communications options for temperature controllers are a hot topic with many engineers. Most companies offer Modbus, ProfiBus, DeviceNet and Ethernet IP communications, and some systems allow multiple communications.

Perhaps the biggest trend today in temperature controls is the ability to communicate to a programmable logic controller (PLC). When communicating to a PLC, it might be necessary to perform block reads, where the controller and the PLC exchange data in large blocks rather than one data register at a time. Some systems utilize common industrial protocol (CIP) commands that allow you to read or write 10 registers with one command to meet these needs. (CIP is a protocol for industrial process automation supported by the Open DeviceNet Vendors Association.)

Multiple PID sets is an option where the controller can switch between various “sets” of PID-based upon temperature. For example, the PID settings necessary to maintain 300°F (14°C) are quite different than the PID settings necessary to maintain 800°F (427°C). With multiple PID sets, you can have the controller switch between these PID sets at a specific temperature.

Related Article: Options Extend Temperature Controls