The tag I am trying to read is as follows (using the Read function on the ControlLogix driver class):
Program:MainProgram.AnalogInSlot3.Ch0InputError
Exception received in 397e
MfgControl.AdvancedHMI.Drivers.Common.PLCDriverException: Read Failed. Invalid Tag Address., Status Code=4
at AdvancedHMIDrivers.EthernetIPforCLXCom.Read(String startAddress, Int32 numberOfElements) in \AdvancedHMIDrivers\AllenBradley\EthernetIPforCLXCom.vb:line 388
I did a wireshark trace and notice that the CIP packets sent with this tag show malformed in the Info column and the tag sent to the PLC itself is different from 397d.
Reading this tag works with the 397d code and the CIP packets do not show up as malformed.