Add Generic ethernet module to RSLogix 5000

I am trying to add a generic Ethernet module to RSLogix and keep getting an invalid size error. There are no inputs, only outputs. I am using input assembly 104 size 0, output assembly 101 size 5. This does not work. If I use input assembly 104 size 1, it works. Sorry, I tried to search the forum for an answer and I keep getting a server error on the PLCS.net end.

Nevermind, I didn't read properly again...

What type of device is it ?

You can create an Connection Type with Input data only (so that you can have a zero-length Output connection) but not a Connection with only Output data.

Most devices have at least a 4-byte status header on the Input side. Try setting the Input assembly to a size equal to 4 bytes (actual number in the field depends on the data type, SINT/INT/DINT).

This is a Wago 750-342 TCP/IP Ethernet remote I/O module. Wago has a software package that helps a person set up the sizes for input and output assembly. That software package was telling me input assembly 104, size zero. I heard back from the Wago engineer and he told me that the coupler does need a size one for status. I entered that and it works fine. It was actually the Wago software that was steering me wonky. I didn't know it but assembly 104 is "inputs plus status". I don't know what the input assembly number would be if there are zero inputs, I cannot find a reference anywhere in Rockwell that shows what these assembly designations actually are. I will use the input assembly 104, size one, and maybe use the status bits later. Thanks for the assistance!

Forgot to mention the Wago software package for anyone else who might be interested. It is called the "WAGO Addressing Tool" (Excel based) and should be available from your local Wago rep. It has saved me doing the math to get the input and output assembly sizes correct.

dkintz said:

It has saved me doing the math to get the input and output assembly sizes correct.

Click to expand...

Well... close anyway

Originally posted by dkintz:

I cannot find a reference anywhere in Rockwell that shows what these assembly designations actually are.

Click to expand...

That's because those aren't defined by Rockwell. They are defined by the 3rd party device manufacturers. This is why it is a variable field in the module definition form and not a dropdown list. There are a range of assembly instance values defined for generic use. It is up to the user to determine what they mean based on the vendor data.

Keith