Change Detect

FactoryTalk AssetCentre can monitor a v20 or higher ControlLogix asset for any changes by continuous polling of the controllers. If a change is detected, it will monitor for any additional changes for a user specified amount of time, then generate a report including all changes during this period. If changes are still occurring after the period has timed out, it will continue monitoring by starting a new period.
Change detect is made possible by FactoryTalk AssetCentre monitoring the controller’s change log. While not as detailed as the disaster recovery compare report, this feature is intended to provide real-time feedback on the controller’s status. The change log is a circular store inside the controller capable of up to 100 entries. In the event of changes to the controller during a disconnect, FactoryTalk AssetCentre will immediately detect the changes upon restoration of communications, and log all changes during the disconnect period. The Change Detect functionality has been tested with a maximum ratio of 1:500, where one agent will monitor a change detect schedule configured with 500 controllers.
This type of schedule is only available for Logix 5000 Controller assets that support and are configured for change detection. For more information, see Schedules and Create a schedule.
The
Change Detect
 option, available under
Tools
, allows you to configure the communication settings between FactoryTalk AssetCentre agent and controllers when performing a change detect task, including the number of concurrent monitoring tasks and the packet size used to read the controller logs when changes are detected.
TIP:
These overall settings can only be modified via
FactoryTalk AssetCentre Desktop Client
>
Tools
 >
Options
 or
FactoryTalk AssetCentre Web Client
 >
Tools
 >
Change Detect
. Any changes made will apply only to new schedules and do not affect existing ones. To apply updated overall settings to previous change detect schedules, deactivate the old schedules first, and then activate them again.
  • Concurrent of monitoring tasks
    Enter the number of concurrent monitoring tasks used for communication between FactoryTalk AssetCentre and the controller. The value must be between 2 and 64, with a default of 32. To use system resources efficiently, consider the number of controllers involved in your change detect schedules when setting this value:
    • For a high number of controllers, for example, 100, setting this to the maximum of 64 enables faster scanning across more controllers at once, but the remaining 36 tasks will be queued.
    • For a low number of controllers, for example, 2, setting this to 2 ensures that no excess tasks are opened unnecessarily, helping conserve system resources.
  • Connection type
    Configure the packet size used to read the controller logs when changes are detected. For example, if the size of a change log entry is 2000 bytes, when
    Use 4000-byte packet connection (reduce network traffic)
     is selected, a change log entry can be retrieved in one read. If
    Use 500-byte packet connection (for compatibility)
     is selected, retrieving a change log entry requires four reads. By default, the
    Use 500-byte packet connection (for compatibility)
     option is selected.
    WARNING:
    Using 4000-byte packet connection option is faster and more efficient, but it can also consume more system resources and impact motion on a controller.
    • Use 500-byte packet connection (for compatibility)
    • Use 4000-byte packet connection (reduce network traffic)
      . To use this option, the following minimum versions are required:
      • Controller firmware revision 20 or later when using the controller’s built-in Ethernet port.
      • Ethernet communication module firmware revision 5 or later when using an Ethernet communication module.
      • FactoryTalk Linx software version 6.60 or later.
Provide Feedback
Have questions or feedback about this documentation? Please submit your feedback here.
Normal