I have one more question on my project (I posted previously a few weeks ago - and THANKS! for the help).

I need to transfer bit and word data via my Twido ethernet port to a Modbus master. It looks like the EXCH3 and %MSG3 commands must/should be used. It appears that these commands can only be used to transfer word data. My question is how to transfer bit data (in consecutive %M registers) to a word.

An example in the manual shows:

%MW100 := %I0:16

what I would like to do is the following:

%MW100 := %M80:16, where the 16 consecutive bits following %M80 would be stored in %MW100. But, that is not allowed.

So, I was wondering if anyone had any suggestions on what I might do.

Thanks,
Steve

Hi
This transfer is perfectly allowed, i don't understand why it doesn't work for you ? Are you sure the syntax is correct in your program ?

JC

Hi JC,

There was a message that said that operation was not available for my processor. The good news is I did figure out how to map them one at a time, which was pretty easy.

Now I'll have to wait and see if I have any comm issues using the EXCH and MSG commands. They look pretty straightforward.

Thanks,
Steve

I know we can use modbus TCP for twido PLC that is supported ethernet. We use EXCH3 to transfer modbus frame from master( client) to slave( server). But in help file we don't have any structure of frame.I know modbus TCP frame has MBAP header, function code, data but I don't know how to apply for Twido. for example I want to read two word from slave: %MW100 and %MW101.
how should I define the table ( frame) and use EXCH3
in twido ethenet port I have configured IP slave address :137.123.12.1, index:1.
thanks