S_Button1 and S_Button2 inputs

These state-controlled inputs evaluate the status of the connected buttons of the two-hand control device (as actuated or not actuated). The S_TwoHandOut output can only be switched to SAFETRUE if both inputs switch from SAFEFALSE to SAFETRUE and remain in this state.

Data type: SAFEBOOL
Initial value: SAFEFALSE

Connection: Connect these inputs to the buttons of the two-hand control device to be evaluated, either directly or via additional 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 these inputs lead to the following function block behavior:

Value Description

SAFETRUE If both inputs S_Button1 and S_Button2 switch from SAFEFALSE to SAFETRUE, either simultaneously or consecutively, the S_TwoHandOut output switches to SAFETRUE. The S_TwoHandOut output remains SAFETRUE for as long as both inputs have the SAFETRUE value.

SAFEFALSE If at least one of the inputs (S_Button1 or S_Button2) is SAFEFALSE, output S_TwoHandOut = SAFEFALSE.

Value	Description
SAFETRUE	If both inputs S_Button1 and S_Button2 switch from SAFEFALSE to SAFETRUE, either simultaneously or consecutively, the S_TwoHandOut output switches to SAFETRUE. The S_TwoHandOut output remains SAFETRUE for as long as both inputs have the SAFETRUE value.
SAFEFALSE	If at least one of the inputs (S_Button1 or S_Button2) is SAFEFALSE, output S_TwoHandOut = SAFEFALSE.

Hinweis
The S_TwoHandOut output can only switch to SAFETRUE if both inputs have been in the SAFEFALSE state before.

Using two-channel buttons

Irrespective of whether there is a single-channel or two-channel connection between the buttons of the two-hand control device and the Sicherheitssteuerung, both inputs S_Button1 und S_Button2 are only connected to one signal each. When using two-channel buttons, each two-channel signal must be evaluated or monitored as follows:

Either through a suitable upstream safety-related function block, e.g., SF_Equivalent, if the button has two N/C contacts.
Or the evaluation of equivalence or antivalence must be performed in the safety-related input device, also see section "Application example".

A single-channel button design for category 3 is only permissible if the safety chain of the connected button of the two-hand control device satisfies the requirements of EN ISO 13849-1 up to category 3 in terms of single-channel applications. With this in mind, the following components in the safety chain need to be considered:

Sicherheitssteuerung, including programming (cross-circuit detection),
the connection and cabling between the Sicherheitssteuerung and the button of the two-hand operator panel, and
the complete two-hand operator panel.

Please refer to the user documentation specific to the devices used in the safety chain for details of other measures which need to be taken.

WARNUNG

Non-conformance to safety function requirements

If two-channel buttons are used:

Ensure that the components in the safety chain (as listed above) satisfy the requirements of EN ISO 13849-1 up to category 3 in terms of single-channel applications.

Be sure that your risk analysis includes an evaluation for using two-channel buttons.