Messages

571

General Mach Discussion / Re: PLC With Analog Input

« on: November 29, 2010, 10:28:36 AM »

It's not really about the money.  I'm just looking for a more "industrial" solution (for lack of a better term).  I have a Sound Logic THC and it works fine, and buying another one is the easy way out, but I think I can build a better one using a PLC.  I also need a PLC anyway because I want to build an LCD touch screen remote.

572

General Mach Discussion / Re: PLC With Analog Input

« on: November 28, 2010, 11:08:21 AM »

Thanks Scott.  That about the logic I had in mind.  I hadn't considered using analog out to a DC motor drive.  The Z still has to be able to be driven by Mach for manual UP/Down jogging and initial height sensing, but that would probably be possible through the modbus link.  My plan was to use a stepper, and use the outputs on the PLC to drive the THC Up and Down inputs in Mach, but after reading your post, I'm thinking the CTRIO may provide a faster pulse rate and better response time for cutting irregular surfaces like corrugated metal.

Do you think the CTRIO would be considerably faster than just driving the THC UP/DOWN mach inputs? Not sure what the max pulse rate is on the PLC outputs.

You mentioned the built in stepper pulse out.  Do you think this would be faster than driving the THC UP/DOWN inputs?

573

Brains Development / Re: Stuck on brain

« on: November 27, 2010, 10:44:22 PM »

Is the non-plugin interface is just a serial connection from the PLC to the PC?  Is there a screen in Mach where you set up the PLC inputs and outputs?  Something like the ports and pins inputs and outputs but for the PLC.

Thanks

574

Brains Development / Re: Stuck on brain

« on: November 27, 2010, 05:08:25 PM »

Hood...What's involved in interfacing the DL06 to Mach3?  Is it just a serial connection then configuring the ModBus in Mach or is there more to it? 

575

Brains Development / Re: Stuck on brain

« on: November 27, 2010, 10:58:04 AM »

Yep...The third one did it.  Thanks so much for your help.

576

Brains Development / Re: Stuck on brain

« on: November 26, 2010, 10:26:01 PM »

I think I've got it.  The decimal thing seems to have something to do with the AND, OR and EOR.  This solution works.  The user DRO stops and stays put when the LED goes out.  When the LED re-lights the user DRO changes to zero then when movement starts, the brain matches it to X position.  That behavior is OK.

What I'm trying to do is create a function that takes the torch back to the last point that the system had a good ark OK signal.  I'm not sure how to handle the G-code yet or if it's even possible.  The problem is that if the THC goes into anti-dive mode, it waits 3 seconds for the voltage to come back into range.  It it doesn't, it shuts the torch down, which causes the arc OK LED to go out.  When mach sees that the arc OK is lost, it pauses the program until it sees a good arc OK.  Problem is that if the torch shuts down in the middle of a command, like the mid point of a circle, the torch shuts down, but mach completes the current command.  The result is that half the circle is left un-cut.

When you rewind the program, you can't rewind and run from the beginning of the last command because you would be cutting air and the THC would shut it down.  You have to somehow rewind and run from the last known position
where the system had a good arc OK signal.

It happens so infrequently that it's hardly worth the effort, but it's a challenge and something cool if I can get it working.

577

Brains Development / Re: Stuck on brain

« on: November 26, 2010, 07:53:08 PM »

Hmm...Interesting...I noticed this earlier when I was playing around with the AND and OR statements.  When it increments the user DRO, it only increments the whole number, not the decimal.  IE:  Everything between 3 and 3.9999 on the oem dro shows as 3.0000 on the user dro.

578

General Mach Discussion / Re: PLC With Analog Input

« on: November 26, 2010, 07:36:05 PM »

Looks like the 05 is not capable of floating point math.  I think I'll need that.  Looks like the 06 is it.

579

General Mach Discussion / Re: PLC With Analog Input

« on: November 26, 2010, 07:16:43 PM »

Thanks guys.  I have a Sound Logic on the automation machine, which also works well on the manual machine.  I don't desperately need another THC but thought that I'd take the opportunity to try and find a better way.  I kind of like the idea of programming all of the THC code into the PLC...If it works.  PLC's are not terribly expensive, so it won't cost much to try.  I think the biggest hurdle is making a voltage divider than delivers a clean and relatively stable voltage.

Hood...Will the D0-06DR accept an analog input without using an add-on I/O module?

580

Brains Development / Re: Stuck on brain

« on: November 26, 2010, 06:51:50 PM »

That's pretty close.  What's happening is that the user DRO is changing to 0 when the LED goes out.  What I'm after is for the user DRO just stop recording when the LED goes out so I know the exact point at which arc OK was lost.  You gave me a good starting point.  Is there a good manual on brains somewhere?  I haven't been able to find anything other than a doc in the user section about setting up brains with modbus.