A Key Transfer Scheme
By turning key 1 or 2 in the key controlled switch configuration, the dual safety circuits are broken and the machine stopped. Key 1 can be used to open door 1 of the safeguarded area A. Key 2 can be used to open door 1 of the safeguarded area B. Key 3 is a safety key that keeps key 1 trapped in the door lock preventing machine restart and can also be used to open a door inside area A. Key 4 is a safety key that prevents machine restart and can also be used to start machine teach mode inside area B using a key controlled switch configuration.
