PowerFlex® 750/520 Series: EtherNet connection issues

The story you are about to read is true. Only the names have been changed to protect the innocent…

PowerFlex® 750/520 Series: EtherNet connection issues

Case Number: 116268
Date Created: 12/09/2010 | Last Updated: 07/02/2017

In this week’s Tech Files, we feature a recent call about a PowerFlex drive not connecting to a ControlLogix® EN2T module, but yet the drive was visible on RSLinx.


Why do I get errors when using 1756-ENBT (or similar) module with a PowerFlex 755 drive?

  • 16#0203 connection request error: connection timed out
  • 16#0110 connection request error: module not configured


  • 20F PowerFlex 753 AC Drives
  • 20G PowerFlex 755 AC Drives
  • 25A PowerFlex 523
  • 25B PowerFlex 525
  • 1756-ENBT


In reference with Knowledgebase Answer ID: 66325 – QoS Compatibility with Embedded Switch Technology products

The PowerFlex 755 v2.00 (and higher) and PowerFlex 527 supports CIP Motion therefore there is a requirement for QoS (Quality of Service) support on the Ethernet scanner. QoS support is also a requirement of a PowerFlex 753/755 utilizing the 20-750-ENETR (Dual Port Ethernet) and PowerFlex 523/525 drives utilizing the 25-COMM-E2P. Even if CIP motion is not used, the scanner and drive still make a QoS connection.

All versions of 1756-EN2T  and 1756-EN3T support QoS. 1756-ENBT needs to be firmware 4.005 and above for QoS support. 1756-ENET does not support QoS at any firmware level. Other scanners are described in the note as well.

NOTE: 1756-ENBT module at this time can not be used in CIP Motion applications with the PowerFlex 755 drive. It will work with the PowerFlex 755 Drive in Non-CIP Motion applications however. Also, for the PowerFlex 527, the 1756-EN2T has to be version 3.1 and up.

For instance, using a 1756-ENBT, you now will need to be v4.005 firmware and above. Use ControlFlash.msi to flash this module. The firmware can be found on the Firmware Updates webpage. You will need an email and password along with your RSLogix 5000 serial number.


Looking for more information?
Contact your local automation specialist or account manager at The Reynolds Company to discuss your automation applications. Find your specialist.