PLC Developers Guide / ZPA Mode Control / PLC Outputs for ZPA Mode /

Set Local Tracking	ConveyLinx ERSC ✅	ConveyLinx-Ai 24V ✅	ConveyLinx-Ai 48V ✅
	ConveyLinx-ECO ✅	ZPA Mode ✅	PLC I/O Mode ❌

Writing Tracking Details

Because the ConveyLinx Module is connected as I/O, the PLC inherently is always trying to update the Output image on (at least) RPI intervals. In order to prevent the PLC from inadvertently overwriting the “real” tracking data registers; the Assembly Output implementation utilizes the holding register locations shown and automatically updates the “real” tracking registers with this new data only upon release of the Carton from the zone. Included in this automatic functionality are two special reserved values that can be used for convenience:

• Set both tracking registers shown to 0: This will instruct the module to not modify the existing “real” tracking data and allow it to continue downstream “as-is” when the Carton is released.
  
  
• Set both tracking registers shown to 0xFFFF: This will instruct the module to clear the “real” tracking data and when the Carton is released, the “real” tracking data will be “0” in both registers.
  

!Both word 1 and word 2 of the tracking data in question must have 0xFFFF written to it in order to signal the module to clear the tracking data. If only one word has 0xFFFF written to it and the other does not, the value of 0xFFFF will be the new tracking data for that word.