Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: lukejs on January 25, 2009, 04:21:24 PM

Title: Sending DRO to modbus device...
Post by: lukejs on January 25, 2009, 04:21:24 PM

I'm building a PIC-based modbus device, and want to send dro information to the device. I've successfully set it up in 'setup serial modbus control', and have enabled cfg #0 as an output/holding register. If I create a brain with a no-operation lobe and the x-axis DRO as an input with the modus cfg #0 as an output, I can see a 16 bit value reaching my modbus device. From what I've read in this topic (,5393.0.html), it seems as of January '08 there was no way of sending the whole dro value using a brain (16 bits isn't enough).

Two questions: 1) is this still the case, or is there a way of sending the whole dro value using a brain?
2) If I can't, is a macropump the only way?

I've tried writing a macro pump, but can't for the life of me figure out the modbus functions. They seem to have a different mapping method from the ones in the current mach3 modbus setup. I.e. I can't work out how to use to use cfg #0 in the SetModOutput() function. SetModOutput takes two arguments as I understand it - the first of which - buffIndex - maps to the modbus output. How do I tell it to use cfg #0?

Anyway, I hope that makes sense. Frankly it's a bit hard to explain as the mach3 nomenclature seems somewhat convoluted, to say the least...

Any help is greatly appreciated!!!