In control when going gets tough

Simatic S7-300 PLC programmable controller modules, dubbed the All-Weather PLC family by maker Siemens, are designed for use in moist and hostile environments. They have an operating temperature range of -25 to +60 and are intended to control machinery as diverse as concrete mixers and sewage pumps.

The controller modules have been developed to withstand shock loadings encountered during rail and road transport.


Computer systems using ‘fuzzy logic’ can be anything but fuzzy in use, according to PLC maker Klockner-Moeller. The company says ‘fuzzy’ technology, which allows finer interpretative distinctions than binary systems, affords precise control in open and closed loop applications that might be considered awkward.

Typically, these include control of more than one process variable, as well as non-linear processes with opposing control objectives, such as temperature and humidity. To promote its latest Windows-based compact PLC, the PS4-401-MM2, the firm is holding fuzzy logic seminars. Details are available from Trevor Blevins on 01296-393 322.