Posted to News on 6th Mar 2008, 13:34
Single-loop PID controller operates as slave to PLC
The ability to accurately measure, display and control temperature values is crucial to industrial applications such as plastic extrusion, injection moulding, thermoforming and food processing. Processing plants must therefore consider many features when selecting a temperature controller.
Eurotherm's compact DIN rail RFS single-loop controller is a cost-effective product suitable for use as a slave PID loop to a programmable logic controller. Many users prefer a single-loop controller to manage each zone of a process; it enables them to link the temperature controllers and zones to a supervisory controller for co-ordination and remote single-point monitoring.
The RFS combines these features. It also has fast response times with single-point monitoring thanks to the Modbus communication interface, plus built-in intelligence.
It has been designed using a Smart PID self-tuning algorithm equipped with soft start and a non-linear cooling function for use on water-cooled extruders. The smart tuning automatically adjusts the unit to existing process dynamics to avoid disruption of current operating conditions.
Smart temperature controllers can be programmed to provide a variety of outputs in response to changing conditions. There are three outputs with the RFS, providing a heat plus two alarms or heat/cool plus one alarm configuration. A complete set of process protection alarm functions with high and low limits or band and deviation are also included.
All inputs and outputs can be read directly over the Modbus interface and the master can write to RFS outputs not assigned as alarm or status functions to simplify machine troubleshooting and enable the system to perform remote diagnostics.
The RFS is easily configured with PC wizard software. The parameters can be modified at any time.
