Slc 5/05 Msg function

[JPCompounds]

Good afternoon.

We upgraded to SLC 5/05 processors a few years back but I don't think our MSG function has been working properly. The data isn't updating but there are no ERRORS listed. I think the command is setup properly but I'm not sure what is going on.

It is set up as a Peer to Peer, Read, 500CPU, Local.

What should the size in Elements be?

Thanks,

 

[Ken Roach]

Post all the details, preferably with screenshots.

There are two data fields associated with a MSG; the Command block, and the Data Block.

You have to be certain the Command blocks don't overlap one another (they are 51 words long, unchangeable, for Ethernet messages) and should also take care to be sure the Data Blocks don't overlap.

The "size" is the number of Data elements (often INT registers) you want to read or write.

Edit: What controller model did you upgrade from ? MSG instructions on the legacy networks (DF1, DH485, DH+) used smaller control blocks and if those addresses didn't change correctly to establish new control blocks for Ethernet, you might have some badly overlapped control blocks.