Hello Guest it is November 30, 2021, 02:27:18 PM

Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.

Messages - lukejs

Pages: 1
General Mach Discussion / Turn motor output on and off
« on: April 11, 2009, 11:55:36 AM »
I'm sure there's a simple way of doing this, but I can't work it out.

To trace a problem I want to be able to toggle the motor outputs (dir and step) for different motors on and off, so I can test the output of my BOB with a multimeter. How can I do this?

Incidentally - the reason why is that one of my axes has started moving only moving in one direction! (And you can imagine the damage this causes.) By switching the outputs from the BOB to my different UHU servo controllers I can see the problem shift to a different axis, so I know the problem is in software, the BOB or the wiring from the BOB to the UHUs. I mention this in case anyone recognises these symptoms and can offer a solution.

Thanks in advance,


General Mach Discussion / Very weird crash/problem
« on: March 11, 2009, 06:19:46 PM »

I was happily cutting out a part on my router earlier this evening when, at the very end of a job, instead of retracing the z axis drove straight down in the table. Thanks to the fact that fitting limit switches is still on my list of things to do, some horrible noises were emitted by my machine before I made it to the estop button. Fortunately no damage appears to have been done, but on resetting my servo drivers (UHUs) and manually retracting the z axis by rotating the lead screw by hand (and pliers), I found that if I attempted to jog the z axis up it would instead go down! Jogging down also sent the z axis down - i.e. irrespective of the direction I attempted to jog the axis moved down. At this point I figured maybe the z-axis direction lead had become disconnected from my break out board, but this didn't appear to be the case and my multimeter seemed to agree. I figured I'd restart the computer before trying anything else. I did this, started mach3 and tried jogging the z axis. It worked fine, going up and down as expected.

So, it looks like I experienced some kind of weird software failure, not a hardware problem. Does anyone have any idea why, and how to make sure it doesn't happen again? Obviously the part was written off, and I could have been left with lots of repair work on my router, so I want to make sure all's well before I continue.

Any suggestions or comments gratefully received!

Brains Development / Re: Trying to make dro positive
« on: February 02, 2009, 01:59:35 PM »
Surely that won't work as Format() returns a string?

Or will it automatically be converted back to a integer?

Brains Development / Re: Trying to make dro positive
« on: February 02, 2009, 07:38:55 AM »
Hi Scott,

That's great, thanks. Perhaps you can enlighten me on something else. What I'm actually trying to do is get a dro value to a modbus device. Now, if I use this formula in a brain I get the fractional part of the DRO: (A-Int(A))*10000. But it seems that DROs are actually stored to greater than 4 decimal places. So if for instance if the DRO actual value is 0.71539, what's displayed in mach3 is 0.7154, but what gets sent to my device is 7153 (i.e. the digits after the 4th dp get truncated rather than rounded). (This is all a supposition based on what's displayed in Brainview). I'm not clear which math operators I can use - for instance I would have thought Round() would be the solution but it doesn't seem to work. Do you know what math operators are available (I hadn't realised Abs worked until you suggested it), or alternatively another way to do what I'm trying to accomplish?

Thanks again,

Brains Development / Trying to make dro positive
« on: February 01, 2009, 08:21:18 AM »

I'm trying to use a brain to test whether the z DRO is negative, and if so multiply it by -1  (i.e. make it positive) before sending it to a modbus device. As you can see in the brainview screen shot attached, it's giving me an output of 0 rather than (in this case) 10.9079. If I make the z-axis DRO positive I get the same output (0). Surely this should work. Can anyone tell me what I'm doing wrong?

Any help is gratefully received.



General Mach Discussion / 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!!!


Pages: 1