'Wiring with keystrokes' - makes logical connections simpler - December 2001

Operator Interfaces, Switches & Relays

Industrial switch & relay suppliers

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'Wiring with keystrokes' - makes logical connections simpler

December 2001 Operator Interfaces, Switches & Relays

Launched a few years ago as an all-in-one, programmable, electromechanical relay, electronic timer, temperature controller and realtime clock, Moeller's 'easy' control has had its capabilities extended to make it a key component in the field of industrial automation.

The capability of the 'easy', which uses logic links instead of wiring, has been enhanced to include ASI communication and Profibus DP communication. Conventional circuit wiring of switching and control devices is replaced by using keystrokes on the relay to make logic connections. This means that wiring and installation costs in industrial applications are greatly reduced. By using the 'easy' as a slave on an ASI network additional digital I/O can be achieved. Similarly, the device can serve as a slave on a Profibus DP network, with all information being accessed from a master PLC. Coupled with these networks, 'easy' becomes an integral part of a scada system, saving the cost of expensive I/O devices.

For straightforward sequences, such as production processes, connecting an 'easy' to an ASI bus can supply 31 stations simultaneously with up to 248 instructions. Input and output data are transmitted in only 5 ms, enabling several motors, for example, to be started at the same time. The Profibus DP system can transfer large sets of data, transmitting up to 20 bytes per station and permitting 126 stations at distances of up to 1200 m to be linked.

The 'easy' control relay continues to play a role in applications such as lighting for shop windows and temperature control in greenhouses. In greenhouses, the relay can handle daylight and temperature-governed control of skylights, heating, blowers and lighting, as well as recording and processing of up to two analog valves.

When used for centralised and decentralised lighting control for buildings the 'easy' can be fitted into low-voltage distribution boards. For cooling systems it can control temperatures in a range from -25 to +55°C, while two analog inputs permit recording of temperatures and pressures.

For machine control, a plug-in memory module enables duplication of the 'easy' circuit diagram without a PC. Any changes to the circuit can be made off-site, the memory module sent to site and the modifications read into the 'easy' there. The 'easy' will detect a short circuit and disconnect transistor outputs selectively.

Rapid and safe commissioning is facilitated because the relay indicates where current is flowing in the circuit, for both testing purposes or in actual operation.

A password function enables selective access to the circuit and parameters such as time and analog comparison, while also allowing users access to specific areas. The 'easy' also has the capability to retain counter and timer values in the event of a power failure, enabling the user to continue from the point at which the process was stopped.

Moeller Electric

(011) 975 3937

[email protected]

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'Wiring with keystrokes' - makes logical connections simpler

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