EtherNet/IP Error -251723760 "Invalid segment type/IOI"

Updated Aug 31, 2018

Reported In


  • NI-Industrial Communications for Ethernet/IP

Issue Details

When I communicate with a PLC using NI-Industrial Communications for Ethernet/IP, I get the following error:


(-251723760) EthernetIP Tag Read/;

Details: CIP Error - Extended status may be available

CIP Status: 0x4 (Invalid segment type/IOI)


Make sure the command you are sending to the PLC is valid:

  1. Check that the Tag prefix you are using is correct.
  2. Check that the Tag name you are using is correct.
  3. Check with the PLC's manufacturer why it would return an error 0x4 when you read/write that tag.

Additional Information

This error is returned when the EthernetIP Tag Read/ receives an error 0x4 as a response from the PLC.