Peter, Hood,
Thanks so much for the help, I've got Mach talking nicely to the PLC now using the start address 16384. Ive even managed to trigger a mini-ladder test program that toggles real outputs on the PLC from a VB script, progress!!
Peter, the ModIP sounds really great, this is pretty confusing and I've got a fair bit of experience with electronics, and micro-controllers. I'd hate to jump into this without any background....
I'm still not totally clear on the bit-packing options, but I may just stick with it the way it is, things seem to be working and if the CLICK will not unpack them properly anyway I'm OK with the inefficiency.
Thanks again, I'm going to experiment more with the script tomorrow.
Dustin