Idec has developed a safety controller that bridges the cost and sophistication gap between safety relays and safety PLCs. The SafetyOne FS1A controller can replace up to six safety relay modules without needing any programming. Compared to conventional relays, it needs less wiring and saves space. It is also much cheaper than most safety PLCs, and costs a similar amount to four or five relays.

The controller (above) is configured by setting a dip switch to one of eight preconfigured logic functions, such as muting or partial stops for interlocks. In operation, LED indicators show I/O status and any errors. The controller meets the requirements of SIL3/Ple/Cat4 and is TÜV-approved, avoiding the need for certification.

The controller has seven dual-channel safety inputs, four safety outputs, and several non-safety inputs, and solenoid drive outputs that can be connected to interlock switches. Time delays of 0–30s can be set on the outputs. The controller can be used with safety- and non-safety components such as emergency-stop switches, interlock switches, light curtains, pilot lights and sensors.