Issue
Controller stops sending Valid and Invalid Access events but other types of events such as Exit Requests events are delivered fine.
Environment
CyberStation
NetController I (CX9900)
Cause
Due to a defect in the firmware the controller can randomly get in a mode where Valid/Invalid Access Events are stuck in the controller and not delivered to CyberStation, the defect has been fixed in the second generation access controllers (CX9680 version 2.100035 and ACX57xx version 1.100037) but not in the older first generation controllers such as the CX99xx.
Resolution
A PE program running in the CyberStation can detect and alert of the condition and also perform an automatic reload to make the controller resume sending the valid/invalid access events.
The following program is provided for illustration purposes ONLY and can be used as a guideline for creating a program in CyberStation to detect that a controller has stopped sending valid access events.