EN ISO 14119 describes the normative basic principles for interlocking devices which are associated with guards, and this handy poster from Pilz might prove useful
The Standard covers measures designed to prevent the defeat of safeguards and their interlocking devices - a forbidden but regrettably still frequent practice. All phases of the machine’s lifecycle must be considered when selecting the appropriate interlocking device, with or without guard locking (in accordance with EN ISO 12100).
Whether in automatic mode, set-up mode or alternative operating modes, it’s necessary to prevent manipulation on all protective measures. This updated poster from Pilz contains information on how to stop manipulation, with everything you need to know presented here in a clear format.
On a similar theme, MachineBuilding.net readers can also readily access the recent (archived) Pilz webinar entitled 'Understanding ISO14119 - Interlock devices' by clicking here.