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Author Topic: Sending DRO to modbus device...  (Read 1876 times)

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Sending DRO to modbus device...
« 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 (http://www.machsupport.com/forum/index.php/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!!!