The PRSU/4 from Tapeswitch is a safety interface controller that connects pressure-sensitive guards — safety mats, sensing edges, ribbon switches, and bumpers — to machine control circuits. Rated Category 3 / PLd per EN ISO 13849-1, it provides redundant, cross-monitored safety outputs that render the machine inoperative upon sensor activation or internal fault detection.

What sensors is the PRSU/4 compatible with?

The PRSU/4 works with any Tapeswitch pressure-sensitive safety device wired in a 4-conductor fail-safe configuration. This includes safety mats for area guarding, sensing edges for automated doors and gates, ribbon switches for perimeter protection, and bumpers for AGV and material handling applications. The controller continuously monitors sensor continuity — a break in any wire or a short circuit triggers an immediate safety stop.

How does the PRSU/4 safety monitoring work?

The unit employs force-guided safety relays in a redundant configuration with cross-monitoring. Upon sensor activation (pressure applied to the mat or edge), both output relays de-energize, opening the three normally-open safety contacts. If either relay fails to open — due to welded contacts or mechanical failure — the cross-monitoring circuit detects the fault and prevents the other relay from re-energizing until the fault is corrected. This control-reliable architecture meets the requirements of OSHA, ANSI, and RIA machine guarding standards.

What is the difference between manual and auto reset modes?

In manual reset mode (default), the PRSU/4 requires a deliberate reset signal after each sensor activation before the safety outputs re-energize — even if the sensor is already clear. This prevents unexpected machine restart when an operator steps off a safety mat. In auto reset mode (enabled by linking terminals S33–S34), the outputs re-energize automatically once the sensor clears, suitable for applications where access control rather than operator presence detection is the primary safety function.