Interlocking in accordance with EN 1088

The EN 1088 standard (Safety of machinery) provides a definition for interlocking devices associated with guards.

Among other things, a distinction is made between

Interlocking devices without guard locking (two-stage interlocking) and
Interlocking devices with guard locking (four-stage interlocking).

Both types of interlocking are shown alongside each other in the diagram below.

NOTE:

Safety-related function blocks are available for both types of interlocking in the EcoStruxure Machine Expert - Safety software, which enable monitoring and evaluation of the safety equipment with the Safety Logic Controller. These function blocks are:

GuardMonitoring: Monitoring a guard with two-stage interlocking
GuardLocking: Monitoring a guard with four-stage interlocking