Installed the new HMI computer in the line today, only had a couple bugs I had to fix, but then when I did a rebuild I got 2 errors:
Unused Local Variable "TNS" in SLCMicro driver.
Unused Local Variable "TNSLowByte" in SLCMicro driver.
The other thing I noticed, the screens load quickly (after the first load) but sometimes take up to 10 seconds to show the status of the PLC, and sometimes clicking on something takes a few seconds to get a reply after the screen has been loaded too.
To speed up the comm's I un-remarked the line & set it to &H5B for a SLC5/04 as suggested, and set all DF1 drivers to 19200 baud from the default 'Auto' so it doesn't look around first. I didn't change anything else in the SLCMicro driver other than that one line.