hi, Bob,
Thanks for your quick reply. I connect the reister just as the schematic in my original post, It takes the place of the pt100 to form a 3 wire connecttion.
The reigister setup values in my original post is read from ADS1248 after i set up the registers, I'm not sure if they are correct for my application but I believe that they are real values in the registers because I read the default values first and compared them with what I posted here.
Maybe ,the volt meter is not preise enough, but I don't beleave it has such a big error.
I have tested the current path with the result in my original post, I think the path is OK.
Best Regards
Allen