S_GuardLock input

State-controlled input for the status of the guard locking on the safety equipment. This input processes the feedback signal for locking/unlocking the safety equipment (single-channel or two-channel).

The signal present must be SAFETRUE so that the S_GuardLocked output can be switched to SAFETRUE (taking the other input signals into account).

Data type: SAFEBOOL

Initial value: SAFEFALSE

Connection: Connect this input to the feedback signal of the interlock of the safety equipment, 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), the possible values at this input lead to the following function block behavior:

Value	Description
SAFETRUE	The safety equipment is locked. The S_GuardLocked output can now be switched to SAFETRUE, provided that the safety equipment is also closed (S_GuardMonitoring = SAFETRUE), no start-up/restart inhibit is active (S_AutoReset and S_StartReset = SAFEFALSE) and the function block has not detected any errors. Refer to the hazard message below this table.
SAFEFALSE	The safety equipment is not locked or the safety equipment wiring has been interrupted or the safety-related input device connected to the safety equipment has been deactivated or is inoperable. If SAFEFALSE is present at the S_GuardLock input, the S_GuardLocked output is always SAFEFALSE, irrespective of all the other input signals.

If no start-up/restart inhibit has been specified for the function block, the SAFETRUE status at the S_GuardLock input can cause the S_GuardLocked output to immediately switch to SAFETRUE.

WARNING
	UNINTENDED START-UP If no start-up/restart inhibit is specified: Be sure that your risk analysis includes an evaluation for the state change at the S_GuardLocked output after applying the SAFETRUE status to the S_GuardLock input. Make certain that appropriate procedures and measures (according to applicable sector standards) have been established to help avoid hazardous situations when applying the SAFETRUE status to the S_GuardLock input. Use appropriate safety interlocks where personnel and/or equipment hazards exist. Failure to follow these instructions can result in death, serious injury, or equipment damage.

WARNING

UNINTENDED START-UP

If no start-up/restart inhibit is specified:

Be sure that your risk analysis includes an evaluation for the state change at the S_GuardLocked output after applying the SAFETRUE status to the S_GuardLock input.
Make certain that appropriate procedures and measures (according to applicable sector standards) have been established to help avoid hazardous situations when applying the SAFETRUE status to the S_GuardLock input.
Use appropriate safety interlocks where personnel and/or equipment hazards exist.

Failure to follow these instructions can result in death, serious injury, or equipment damage.

Single-channel or two-channel feedback signal for locking/unlocking?

Irrespective of whether there is a single-channel or two-channel feedback connection between the guard locking and the Safety Logic Controller, the S_GuardLock input is only connected to one signal.

If a two-channel signal is used, either the input channels of the safety-related input device must be parameterized accordingly or the safety-related SF_Equivalent or SF_Antivalent function block must be connected upstream for evaluation (e.g., SF_Equivalent function block, if the connected switch features two N/C contacts).

NOTE:

Cross-circuit monitoring is not performed by the function block. It is your responsibility to perform this monitoring function outside of this function block in the safety-related control system.