Looks like you and I are trying to do the same thing.

It seems that your simply looking to poll modbus registers, and write them.

Here's what I found.

There are two types of groups.

Group one are experts at doing just this.
Group two are experts at taking the data and putting it on a slick graph.

I spent 6 months on this same project last year, only to get frustrated and quit.

I think we should collaborate.

Drop me an email response.

Thanks.

Greg