Rockwell Automation 20G PowerFlex 755 Drive Embedded EtherNet/IP Adapter - Manual (Page 183)

Rockwell Automation Publication 750COM-UM001E-EN-P - October 2013 183
Glossary
Zero Data When communication is disrupted (for example, a cable is disconnected), the
adapter and drive can respond with zero data. Zero data results in the drive
receiving zero as values for Logic Command, Reference, and Datalink data. If the
drive was running and using the Reference from the adapter, it will stay running
but at zero Reference.