S_EnableSwitchCh1, S_EnableSwitchCh2 and S_EnableSwitchCh3 inputs

S_EnableSwitchCh1 is the state-controlled input for the signal from the N/O contact E1 of the connected manually actuated, three-stage enable switch.

S_EnableSwitchCh2 is the input for the signal from the N/C contact E3 of the connected enable switch.

S_EnableSwitchCh3 is the input for the signal from the N/O contact E2 of the connected enable switch.

Data type: SAFEBOOL

Initial value: SAFEFALSE

Connection: Connect these inputs to an enable switch connected to the Safety Logic Controller, either directly or via other safety-related functions/function blocks. Constant SAFETRUE or SAFEFALSE values are not permitted.

If the function block is activated (input Activate = TRUE), it evaluates the following:

• The signal level of contact E1 at input S_EnableSwitchCh1 and

• The signal level of contact E3 at input S_EnableSwitchCh2 and

• The signal level of contact E2 at input S_EnableSwitchCh3 and

• signal equivalence at its inputs S_EnableSwitchCh1 and S_EnableSwitchCh3. The allowed discrepancy time is set via the DiscrepancyTimeCh1_Ch3 input.

The function block performs these evaluations for switching stages 0, 1 and 2, as shown in the diagram below: