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Author Topic: Upgrade to Mach 3 / 4 Linuxcnc from PLC, using Panasonic A4 servos.  (Read 14375 times)

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Offline richy

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Hi Everybody

What I have here is a Flow waterjet machine that is driven by a PA8000 Rockwell Automation PLC and a windows based pc system.

We are in Thailand and have no support engineer backup for any of the PLC or the windows software and as the machine is business-critical, I have been tasked to convert this machine to run a linux based program if at all possible. The gaffer has a real dislike for anything windows based and to be honest and we are awaiting mach4 which I saw is going to available on the linux platform. The purpose of this thread will be to show in detail what needs to be done to connect mach 3 /4 / linux cnc and Panasonic servo drives, and, when I lose my way, hopefully get some help from the esteemed readers on here who helped out so much on previous threads like this one:

http://www.machsupport.com/forum/index.php/topic,24005.0.html

Ok I'm gonna go and take a bunch of photos and post those up so you can see what this thread is going to be all about  ;D

Offline Hood

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Re: Upgrade to Mach 3 / 4 Linuxcnc from PLC, using Panasonic A4 servos.
« Reply #1 on: January 21, 2014, 07:11:08 AM »
I wouldnt be holding my breath for Mach4 on Linux. As far as I understand it will be  quite a while after Mach4 is out that it will be ported to Linux, could be wrong but....
Hood

Offline richy

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Re: Upgrade to Mach 3 / 4 Linuxcnc from PLC, using Panasonic A4 servos.
« Reply #2 on: January 21, 2014, 08:03:47 AM »
Thanks for the update Hood, the news that mach is coming to linux is enough for us, we will wait.

In the meantime we will use both linuxcnc and mach 3 in this build and see which one works out best for our requirements.

Here is the machine we will be modyfying.... 60,000 psi pump, watertank, cutting head and 3 axis powered by three different sizes of Panasonic ac servo motors, x and y motors drive the ballscrews via a pulley arrangement, z axis is driven directly by the smallest of the three motors.

Offline richy

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Re: Upgrade to Mach 3 / 4 Linuxcnc from PLC, using Panasonic A4 servos.
« Reply #3 on: January 21, 2014, 08:11:56 AM »
Here is the control cabinet, the plc is contained in the shiny box near the top



This mess has to go....



Control panel showing software, this thing takes about 5 minutes to boot up in the morning and is buggy as hell.......generally a nightmare to work with. The memory appears to be a similar size to that of the zx81 I had for christmas in 1986  :D



Offline richy

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Re: Upgrade to Mach 3 / 4 Linuxcnc from PLC, using Panasonic A4 servos.
« Reply #4 on: January 21, 2014, 08:15:51 AM »
Here we have the three Panasonic A4 servo drives, I've spent the last couple of months trying to make sense of the 380 page manual for these things. I think I have a good grasp of what it takes to hook these up. Time will tell  ;)

Offline richy

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Re: Upgrade to Mach 3 / 4 Linuxcnc from PLC, using Panasonic A4 servos.
« Reply #5 on: January 21, 2014, 08:43:05 AM »
This machine has 24volt Omron NO NPN proximity switches. After much studying and reading on the internets, we realised that these were not ideal, we ordered a few of the same Omron switch but they are NC and PNP, which I'm hoping will hook up to this 24 volt breakout board from cnc4pc, the postie will be here with those any day now.



Page 7 of the manual for that breakout board (attached at bottom of this post) seems to indicate I can connect those switches directly to the boards sinking inputs.

In the ace thread I linked to earlier it was pointed out that I would need line drivers, those are on their way with the BOB right now from cnc4pc dot com.

Offline richy

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Re: Upgrade to Mach 3 / 4 Linuxcnc from PLC, using Panasonic A4 servos.
« Reply #6 on: January 21, 2014, 08:57:59 AM »
Anybody used those line drivers before? The manual for them doesn't spell things out clearly for an idiot like me  ::)



I'm thinking that the GND and +5v I can get from the BOB and that "channel A" could be "DIR pin 2" from the breakout board.

"Channel B" could be "STEP pin 3" from my breakout board? Does that make any sense?  :D

On the output side that would mean pin 5 and 6 would be the differential DIR signals - & + that get fed into the panasonic drivers?



Offline Hood

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Re: Upgrade to Mach 3 / 4 Linuxcnc from PLC, using Panasonic A4 servos.
« Reply #7 on: January 21, 2014, 09:04:48 AM »
Personally I would look at the motion controllers that work with Mach that have 24 I/O.
Also not looked up the drives but if they can be driven with +/- 10v analogue signal I would go that way rather than step/dir.

Drawback to that is the motion controllers wont work with Linux, you would need a different interface for LinuxCNC and atthis time that wouldnt work with Mach.

Hood

Offline richy

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Re: Upgrade to Mach 3 / 4 Linuxcnc from PLC, using Panasonic A4 servos.
« Reply #8 on: January 21, 2014, 11:29:19 PM »
Hood, these drives here have pos, vel and torq mode, they are running in velocity mode now so I'm guessing that this csmio product would be perfect for running + - 10v analogue signals:

http://www.cs-lab.eu/en/index.php?m=gallery&s=show&fid=61&sort=&uinfo=CSMIOIPA_Ethernet_Motion_Controller__Analog__10_V

Problem is csmio stuff is aimed at mach 3 though it seems? and therefore windows for now, and at 599 Euro's it's a non-starter not because of the price but because it's not compatible with our long term goal of only having linux site-wide.

I think we'll press on with step / dir for now, see how that pans out. We got a few of the 50 pin connectors for the a4 drives today and test cable is being soldered up. Installed the Panaterm software on a pc so the parameters in the drive can be changed and saved remotely, still waiting for the proprietary cable in the post for that though.

Offline richy

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Re: Upgrade to Mach 3 / 4 Linuxcnc from PLC, using Panasonic A4 servos.
« Reply #9 on: January 21, 2014, 11:51:14 PM »
For running step dir signals from mach 3 linux etc you'll need position control mode selected in your driver.

In our case that was parameter PR02 which is set to "0"

Here's page 83 of the manual showing the connections that need to be made.......



Full manual for these drives can be downloaded here http://pewa.panasonic.com/downloads/a4/