Modbus and me. Switching from Mach3?
Two thing are making me look at switching to LinuxCNC. First, I replaced the 3hp spindle motor on my mill with a 3.5kw Mitsubishi brushless servo and got rid of all the vary-speed stuff. This works freeking awesome, oodles of power at all speeds. Since the motor is tied directly to the spindle with a HTD timing belt I now have the option to do rigid tapping with the feedback from the servo drive. Of course mach does not support this, I have cheated and manually programmed code to do a tap cycle but that is a pain and just waiting for me to screw up a calculation and give it the wrong lead for a thread and crash something.
This leaves me with two choices, Something like a kflop while retaining mach or LinuxCNC. Either way the hardware is going to be about the same price. The issue for me is my pendant. It is a Fagor pendant that Peter Homann reprogrammed for me years ago. It runs on modbus just like his ModIO boards. It is the same as this: www.homanndesigns.com/store/index.php?ma...th=15&products_id=28 , He bought a bunch and reprogrammed them and made new labels for them.
What is stopping me here is how do I configure the pendant to work with EMC? I have no knowledge of modbus or it's protocols.
Next is the lathe. Mach3 on a parallel port sucks. The parallel port driver is screwed up and is not going to be fixed anytime soon. I can use the machine and thread something. Come back a week later and mach will no longer work. So again, two choices again, external motion controller like a smoothstepper or LinuxCNC. There is already an encoder on the spindle so I can tir LinuxCNC right into it. The problem, again, is modbus. The toolchanger on the lathe is controlled by a ModIO from Peter where he made a custom firmware for me to control it.
So, can anyone help me get these two things working?
Please Log in or Create an account to join the conversation.
What is stopping me here is how do I configure the pendant to work with EMC? I have no knowledge of modbus or it's protocols.
...
The toolchanger on the lathe is controlled by a ModIO from Peter where he made a custom firmware for me to control it.
I don['t think that either of these is going to be trivial.
How do they hook into Mach? I guess there is a plugin? Can you see the source-code of the plugin to figure out what goes on internally?
This might be a candidate for a new, unproven, generic Modbus module:
sourceforge.net/tracker/?func=detail&ati...578419&group_id=6744
If you download the patch file and open it in a text editor you will find a great deal of gibberish. However, if you look at lines 2057 onwards you can see some sample configuration files.
If you can work out enough information to populate a config file like that for your devices then it all ought to be possible.
That will get the Modbus signals into the LinuxCNC Hardware Abstraction layer. You would then need to hook them up to the correct pins, but that will be much like any other joypad / mpg or toolchanger example.
Please Log in or Create an account to join the conversation.
Have you looked at the 5i25 servo and stepper PCI cards from Mesa?
Also on my CHNC lathe I do 95% of the ops using ngcgui without any g code programming.
linuxcnc.org/docs/html/gui/ngcgui.html
John
Please Log in or Create an account to join the conversation.
The pendant does have a plugin. I think it configures the switches and the like for mach so a user does not have to go in a set everything up manually in Mach. I had looked at the modbus module a couple months ago and that kind of gave me hope. I dont even know if LinuxCNC can handle MPG input data from serial data.
The tool changer required logic that I would have had a hard time programming in Mach3's macro or brains logic system. And since Peter did not charge me for the custom firmware $100 for the board ready was a whole lot cheaper than my time to try and get this thing working on my own.
I should be able to get the info on how the pendant and tool changer communicate.
IF i can get this to work I will probably buy the mesa cards to do this. Otherwise I will stick a smoothstepper in the lathe and a kflop in the mill.
Please Log in or Create an account to join the conversation.
My CHNC page has all the configurations I used.
gnipsel.com/shop/hardinge/hardinge.xhtml
Is your tool changer more than just an output or two and some inputs and possibly an absolute encoder?
As for the MPG those signals are so slow it can be read even by Mach. Sorry I tried mack once...
John
Please Log in or Create an account to join the conversation.
The wiring is a mess as it is:
![File Attachment:](http://farm5.staticflickr.com/4136/4904116192_5f52db7bd9_b.jpg)
IMGP2363 by macona , on Flickr
Please Log in or Create an account to join the conversation.
linuxcnc.org/docs/html/ladder/classic_ladder.html#_modbus
John
Please Log in or Create an account to join the conversation.
Yeah, I am expecting this to go nowhere, but I figure it is worth a try.
I just noticed that there is already a LinuxCNC component for ModIO:
wiki.linuxcnc.org/cgi-bin/wiki.pl?ModIO
I think this is somewhat out of date. For example I have a feeling that it _can_ be compiled and installed with comp.
(Also, references to EMC2 need to be to LinuxCNC)
Even if you stick with Mach for the mill, it might be worth converting the lathe as LinuxCNC does seem to be a bit better for lathes than Mach is.
The Mesa 7i73 appears to be _very_ similar to the ModIO, but clearly costs more than keeping the ModIO which you already paid for.
Please Log in or Create an account to join the conversation.
I went though the emails between Peter and I when I was getting this thing going. Found the info I need to get it working, I believe.
There are three input registers on the modio,
1100 - Number input here will be the next tool it moves to (1-8)
1101 - Change this register to activate tool change
1140 - Reset, homes the tool changer.
Four output registers:
register 1200 contains the current turret tool position
register 1201 total tool changes
register 1202 contains an error code if things go wrong. 0 is Good
register 1203 displays what state the modio is in during the change (debugging)
Please Log in or Create an account to join the conversation.
I am right now doing refurbish as well and Look into the PoKeys56U boards.
So How did your Journey end ?
Please Log in or Create an account to join the conversation.