What Is A Programmable Temperature Controller?
A Programmer or Profiler is a temperature controller that can be configured with multiple setpoints that are sequenced with preset timing criteria. In its simplest form this can be one profile made up of multiple segments.
Each segment relates to a temperature point (the setpoint) that needs to be reached and held for a desired amount of time. The different segments in a program may include; Ramp, dwell, step, loop, hold and jump segments. A basic form of profiling is also available consisting of two segments and is known as a temperature controller with ramp/dwell control function.
In a programmable temperature controller, the programs are also referred to as profiles and recipes. There are a number of programmable temperature controllers available which can store multiple ‘recipes’ allowing the programmable controller to be used for a variety of processes e.g heat treatment of metals and composites. With some instruments it is possible to set the programs (profile, recipe) to be joined and/or repeated.
The complexity of your temperature control process will dictate how sophisticated the programmable controller needs to be.
What To Look For When Choosing A Programmable Temperature Controller?
When choosing a profiler the number of segments and programs that your process and application needs will be your first concern. These range widely between instruments, for example in the West Control Solutions product offering the PMA KS 40-1 includes a basic programmer function which allows up to 4 segments with 1 program however the new Pro-EC44 dual loop temperature controller from West allows up 255 segments and 64 programs.
Other options to consider when choosing a programmable temperature controller include:
HMI & Display
This is particularly important if you will be expecting users to make regular profile selections via the menu interface. A text display can make the selection process much easier and minimise errors.
Outputs and Event Options
Programmers will vary in the number of outputs available and how these are used. In addition to main control and alarms, outputs are often assigned as profile events and are activated for associated control whilst specific segments are running . Again the the process will dictate your requirements here.
Remote Input
This can allow remote programme selection as well as remote run, hold and reset options.
Real Time Clock
This is not commonly available on programmable controllers but it is a very useful if your process needs to work in real-time.
Data Logging
As one would assume, a programmable temperature controller with a built-in data logger allows important process data to be logged and stored for later analysis. This can be a key requirement to meet some industry regulations or where a process audit trail is required. You may also require this data to be available for interrogation on a PC, if so you will need to consider communications option or a USB port.
