The XPSUS safety relays / safety switchgear can monitor up to two redundant safety functions. However, only one two-hand control panel and one enabling switch can be connected. The XPSUS are designed to monitor two-hand control panels type IIIA or IIIC, which must comply with the international standard ISO 13851. The control consoles must be designed and installed in such a way that they cannot be operated unintentionally or bypassed in a simple manner. Depending on the application, the requirements of Type C standards specific to the machine involved must be met (additional personal protection measures may be required). To initiate the hazardous operation, both operating elements (two-hand buttons) must be actuated within a period of ? 0.5 s (synchronous actuation). If only one of the two buttons is released during the dangerous movement, the control command is cancelled. The continuation of the dangerous operation can only be initiated again when both pushbuttons have returned to their initial position and are actuated again within the specified time period. The safety distance between the control units and the hazardous area must be large enough so that when even one of the two control units is released, the hazardous area cannot be reached until the hazardous work movement has stopped or ended.

With automatic, manual and monitored start as well as start-up test, the following protective devices can be monitored by the XPSUS safety relays:

2 emergency stop circuits according to ISO 13850 standards

Switches activated by protective devices according to ISO 14119 standards:

- 2 mechanical safety switches (position switches, emergency pull-wire switches, etc)

- Magnetic switches with antivalent or 2 NC contacts

- 2 proximity switches with antivalent contacts

- 2 independent PNP sensors

- 2 RFID safety switches

Type 4 light curtains according to IEC 61496-1, which have semiconductor safety outputs with test function (OSSD)

Only with automatic start, the XPSUS safety relays are used to monitor two-hand controls IIIA, IIIC or enabling switches.

The required safety function (1 of 10) can be selected and the start function configured via the selector switches on the front. The diagnostic output transmits extensive status information for simplified maintenance and service via a coded telegram to the standard input of a PLC, which processes it further by means of a function block for common control systems. To monitor a higher number of antivalent contacts with these safety relays, the antivalent contacts can be connected with a normally closed contact (NC) in series and with a normally open contact (NO) in parallel. Six front LEDs provide information on the status of the monitoring circuit.