Logic block controller nears micro PLC functions

Logic block controller provides a programmable, space saving flexible alternative to contactors and relays and has functionality benefits close to that of a micro PLC.

Mitsubishi has launched 'Alpha 2' a new model in its Alpha logic block controller family.

It builds on the groundbreaking original Alpha controller, which redefined the way in which small or simple tasks can be automated by providing a programmable, space saving flexible alternative to contactors and relays.

The Alpha 2 brings these benefits closer to the functionality of a Micro PLC.

A program capacity of 200 functions and fifteen new function blocks open up new possibilities in all areas of building and industrial automation.

The function blocks include maths operations, PWM, two high-speed counters and SMS text messaging when connected to a mobile phone or a GSM modem.

The large backlit screen features display options including bar graphs and scrolling text.

Available in base units of 14 and 24 points, optional extension units can increase the base I/O count by an additional 4 points.

Alpha 2 has an integrated power supply, CPU, I/O, and DC models allow up to eight standard inputs to be reconfigured as 0-10V analogue inputs.

The analog inputs aid user friendliness in the industrial automation environment and are seen as a great advance for building automation projects, where parameters such as temperature, light, and humidity are being monitored.

As an example the standard 0-10V capabilities can be expanded by using the new temperature converters, which allow K type thermocouple (-50 to 450 deg C) input or pt100 input with a range of -50 to 200 deg C.

This makes the Alpha 2 ideal for simple temperature control in buildings as well as some basic refrigeration and oven control for example.

Similarly useful capabilities include the timer function that can be used to 'power down' a room during the night, weekend or other extended periods of expected non-occupancy.

Alpha 2's low cost is also expected to be attractive to both industrial maintenance engineers and building services engineers, who are typically retrofitting distributed intelligence to commercial or public premises to achieve energy savings and who need to be confident of a rapid recovery of capital outlay.

The 24V power supply was developed for Alpha 2 in response to a growing market demand that is being driven by the increasing size and popularity of distributed control systems.

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