What is the maximum number of Access Events a controller can hold?

Issue

The AccessEventSize system variable determines the number of events to retain in a controller when it goes offline, what is the largest value you can enter?

Product Line

Andover Continuum

Environment

Access Control systems using the Netcontroller II (9680) and ACX57xx (5740, 5720)

Cause

When designing an access control system, it is often required to know how many access events a controller will retain if the network connection to the workstations is lost.

Resolution

  1. There is no fixed maximum number you can enter in the EventLogSize, it is dependent on the available free memory in the controller (Freemem).
  2. Typically you should have enough available memory be able to enter a maximum value between 100,000 and 170,000, but this will use up the majority of the controllers available memory.
  3. This may be OK if you are only doing Access control with the controller, but if you are also doing:
  • BMS functions then you may have requirements to store logged data for temperatures etc. 
  • Or you may be using X Drivers with thousands of numeric points

          These would all use up the free memory and may only allow you to hold a few thousand events.

 You have the flexibility to set the value, but the controller will not allow you to enter values that would exceed its available memory.