DiscrepancyTime input
Specification of the permissible discrepancy time for the closing operation of the safety-related equipment.
Data type: TIME
Initial value: #0ms
If S_GuardSwitch1 or S_GuardSwitch2 switches to SAFETRUE, the respective other input (S_GuardSwitch1 or S_GuardSwitch2) must also switch to SAFETRUE within the time set at DiscrepancyTime for the switching operation to be considered as valid. Unless both inputs have switched to SAFETRUE after the time set at DiscrepancyTime has elapsed, an error message is generated (Error = TRUE). The S_GuardOut output remains SAFEFALSE.
Connection: Connect this input to a time literal, i.e., to a constant of the data type TIME.
Background: As a result of mechanical influences, signals may have a tolerance when closing the safety-related equipment (switching the contacts of the position switches). By specifying the DiscrepancyTime value, the time period is defined within which the switching operations at inputs S_GuardSwitch1 and S_GuardSwitch2 must occur to be recognized as simultaneous. This means within the set discrepancy time both inputs may have different states during the closing operation. After that time, the function block detects this as an error.
| Hinweis
If the discrepancy time is exceeded when the safety-related equipment is being closed, an error message is generated (Error = TRUE). The S_GuardOut output remains SAFEFALSE. |
| Hinweis
If only one signal reports the status of the door (one position switch only), this must be connected in parallel to both inputs S_GuardSwitch1 and S_GuardSwitch2. In this case, a time of 0 seconds must be set at DiscrepancyTime. |
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WARNUNG
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Non-conformance to safety function requirements
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