[RQ7.6] The MonitoringNumber in the ResponseSPDU shall be a copy of the MonitoringNumber received in the corresponding RequestSPDU. See 7.2.3.1.

NOTE The SafetyConsumer uses the ResponseSPDU.MonitoringNumber to detect SPDUs received with timeliness error, e.g. SPDUs which are continuously repeated by an erroneous network element which stores data. A different MonitoringNumber is used in every RequestSPDU of a given SafetyConsumer, and a ResponseSPDU will only be accepted if its MonitoringNumber matches the MonitoringNumber in the corresponding RequestSPDU.