S_OpMode input
This state-controlled input evaluates the status of an upstream safety-related application or a connected safety-related periphery.
As a consequence, the safety-related function in the connected safety-related periphery is either requested or not via the S_SafetyRequest output. When the function block is activated and as long as no error is detected (Error = FALSE), the signal at the S_OpMode input switches the S_SafetyRequest output synchronously and independent of the states at the other inputs.
Data type: SAFEBOOL
Initial value: SAFEFALSE
Connection: Connect this input directly or via additional safety-related functions/function blocks as follows:
- Either with a signal from the safety-related application, which represents the status of the evaluated safety-related function(s). This can be the enable signal of a single upstream safety-related function block (e.g., SF_EmergencyStop) or the logical connection of the enable signals of several upstream function blocks (e.g., enable signals SF_EmergencyStop, SF_GuardLocking, SF_ModeSelector, etc. connected via S_AND or S_OR).
- Or directly with the status signal of a connected safety-related device (e.g., safety equipment, mode selector switch or emergency-stop control device). In this case, the SF_SafetyRequest function block takes over the evaluation of the connected safety-related periphery itself (instead of another upstream safety-related function block, like for example SF_EmergencyStop).
Constant SAFETRUE or SAFEFALSE values are not permitted.
If the function block is activated (Activate = TRUE), the possible values at this input lead to the following function block behavior:
| Value | Description |
|---|---|
| SAFETRUE | The safety-related function in the connected safety-related periphery is not requested (normal operation). |
| SAFEFALSE | The safety-related function in the connected safety-related periphery is requested. |
Single-channel or two-channel connection of the periphery?
Irrespective of whether there is a single-channel or two-channel connection between the safety-related periphery (e.g., emergency-stop control device) and the Sicherheitssteuerung, the S_OpMode input is only connected to one signal.
When using a two-channel periphery, the two-channel signal must be evaluated or monitored as follows:- Either through a suitable upstream function block, e.g., SF_Equivalent, if the connected periphery has two N/C contacts.
- Or the evaluation of equivalence or antivalence must be performed in the safety-related input device.