I ran into an issue adding a small Protos-X I/O rack to an Automation-Direct P3-550E PLC using a Protos-X PX-EIP1 Ethernet/IP head.

It's added as a generic Ethernet/IP device and as such you have to specify the Input, Output and Config Assembly sizes and provide correctly sized arrays in a straight-forward fill-in-the blanks process.

I had initially configured the Protos-X I/O rack head using the Protos-X Configuration software (version 2.0.2.8) and this software displays the sizes of the Input, Output and Config assembly sizes for the rack that the PX-EIP1 head is connected to. It's handy because it auto-detects all the cards you have in the rack. Nothing could be simpler... unfortunately that wasn't the case. When I enabled the communication with my new Protox-X I/O rack, I got an error message saying that there was a size mismatch with one of the assemblies that I had specified a size for during the process of adding the Ethernet/IP head as an Ethernet/IP device to the PLC.

Automation-Direct also happens to provides a link to an Excel spreadsheet that you can use to build your rack configuration and provides you with the layout of the information that is exchanged between the PLC and the I/O rack. It's a very handy way of determining where the Inputs, Outputs and status bits and words reside in the arrays you provided for the Input Output and Config assemblies. To my pleasant surprise, the spreadsheet tool also provides the sizes of these assemblies and as it turned out, one of the assembly sizes was different from what the Protos-X Configuration Software calculated. When I used the assembly sizes as calculated by the spreadsheet, the size mismatch error was gone and everything now works like it should.

I'm posting this in case anyone else runs into the size mismatch problem and also to alert Automation-Direct of what appears to be a bug in the configuration software.