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Author Topic: Out-Of-Band Axes in Hobby vs Indusrial  (Read 2248 times)

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Offline smurph

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Re: Out-Of-Band Axes in Hobby vs Indusrial
« Reply #10 on: May 10, 2018, 01:03:32 PM »
Yes.  As long as you keep things from getting split brained. 

Steve
Re: Out-Of-Band Axes in Hobby vs Indusrial
« Reply #11 on: May 10, 2018, 01:33:23 PM »
Awesome!  I'll check to make sure that HiCON Can use the OOB Axis, it controls 6 axis.

I plan on using an OOB Axis for a SMTC carousel and I would like to rotate it freely with the Click PLC as well as in Mach.

I'm thinking about having the Axis be based on a register value and letting the PLC Script move the axis based on what that value is.   I can manipulate the register easily enough from Mach or the Click.

Does that sound plausible?

Have you used a Click PLC before? I have used one twice and I am really underwhelmed. The very limited functions wound up costing far more money for programming than the cost savings on the hardware. On the other hand we are thrilled with the Domore BRX PLCs from AD. Ethernet, analog, modbus, highspeed I/O with motion commands, free programming software, autotune PID, modularity, a low price. What’s not to love?
Re: Out-Of-Band Axes in Hobby vs Indusrial
« Reply #12 on: May 10, 2018, 02:13:10 PM »
Yes.  As long as you keep things from getting split brained. 

Steve

What do you mean split brained?

Garyhlucas,
I have used both the Click and the BRX.  Here are my thoughts, for what its worth.
The BRX is extremely powerful and the cost can't be beat for what you get.  So many features and easy to use software. 
The Click is an unbeatable cost for function, IMHO, and is powerful enough to use.

I like the Click matched with Mach4 because it is easy to interface the TCP Modbus.  And the most difficult thing I control is the Tool Change with the PLC and that's easy to program. 
Also, since I don't connect machines to any outside network, I don't have to set up each modbus contact.  I just start my Modbus range with the Modbus address on the click and I don't have to configure anything else.
I use the Click because it does what I need and doesn't have the extra bells and whistles sitting there looking pretty because I don't use them. 

But again, the BRX is an awesome little PLC! 

Chad Byrd
Re: Out-Of-Band Axes in Hobby vs Indusrial
« Reply #13 on: May 10, 2018, 07:27:20 PM »
Hi,
Quote
Contrary to the feature matrix on the website, the Hobby version has all 6 OOB axes available.
Kool!
Quote
OOB axes use the scripting jog methods for motion and they can be homed.  So one can use incremental or absolute jogging for precise positioning.
Kool!

Quote
No G code will ever move one of these axes in coordination with any other axis.  Meaning that no axis letter can be assigned to them.
Well that explains why I couldn't 'see any means of controlling them' even in Industrial.

I have some serious experimenting to do. The ESS allows up to six motors. I'm thinking three (co-ordinated) for the three
axes, one for regular spindle and one for an indexing spindle/axis. My application requires that the spindle be indexed
at certain times. My plan is to have two motors out-of-band motors, one as a free running spindle and the second
indexing spindle and the step/dir signals selected by an output of the ESS.

Now only have to work out how to keep track of the reference position during that time where it is used as a free
running spindle....that may be a challenge! May be required to re-reference when entering indexing mode on each
occasion.

Fun...fun....fun

Craig
My wife left with my best friend...
     and I miss him!

Offline smurph

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Re: Out-Of-Band Axes in Hobby vs Indusrial
« Reply #14 on: May 10, 2018, 10:58:04 PM »
M19 is usually used for spindle orientation.  It is an interface script that should eventually call the "spindleorient.mcs" script.  You only need to find the index pulse once (home the spindle, so to speak).  Then you can mathematically calculate where it is by the number of counts per rev on the encoder, assuming the encoder is 1:1 with the spindle shaft (highly suggested).    Rollover may be an issue.  Use and encoder with the lowest resolution needed to get the job done to keep rollovers at bay.  Just re-home if you detect a rollover.  However, most M19s will spin at a certain speed and find the index pulse every time and then index from there. 

We don't define the arguments to M19, as there are so many variations from the MTBs.  So Brett has just done up and example M19 that can be used as a starting point.  I might be in the newest builds.  It uses R and P arguments to the M19 script.  R is the angle to orient in degrees and P is the direction to orient (0 == shortest path, 1 == clockwise, 2 == counter clockwise).

Steve
Re: Out-Of-Band Axes in Hobby vs Indusrial
« Reply #15 on: May 11, 2018, 12:31:38 AM »
Hi Steve,
I'd been contemplating how to go about retaining 'reference' during free running mode.

My spindle (the grunty high torque one) is based on an Allen Bradley servo and is 1:1. The encoder is available
as outputs from the drive, 8000 count/rev. If I track the encoder with a MPG input to the ESS and subtract
8000 from the count at each 'zero crossing' or index event it should prevent a counter from overflowing
and therefore retain 'reference'.

The only time where I would be concerned about the number of complete turns in addition to the angle within
the current revolution would be when I was rigid tapping and then I would be using the spindle as a C axis
coordinated with the rest of them.

Looking forward to viewing the M19.

If someone were to question 'do you need all this crap' I would have to answer no, but its so much fun fiddling
with all this....and a hobby should be fun right.... even if it doesn't make sense!

Craig
My wife left with my best friend...
     and I miss him!
Re: Out-Of-Band Axes in Hobby vs Indusrial
« Reply #16 on: May 11, 2018, 03:38:34 PM »
I'm doing some bench tests on this OOB Axis.  

I've got it to move using the mc.mcJogAbsStart.  I can move it to "Absolute Position" but I have no idea where to find this position.  How do I check the Position of this motor?  I tired using mc.MotorGetPos and it only returns 0.  

Is there a register that displays this value?  I really need to know the position of this motor so I can communicate real time positions between Mach and the PLC.

I'm going to look at the homing of this motor next.  
Chad Byrd

Offline smurph

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Re: Out-Of-Band Axes in Hobby vs Indusrial
« Reply #17 on: May 11, 2018, 03:54:02 PM »
The motion controller may not be reporting feedback for motors on the OOB axes, if that is the case.  It should.  Make sure you are passing the correct value for the motor ID.  Check the return code of the API function!!!  :)  See if there is an error code.  If all is well, then there is something wrong with the motion plugin.  Typically, you would use mcAxisGetMachinePos() to get the position in machine units for the axis.  mcMotorGetPos() for the motor that is attached to the OOB axis should return the motor counts.  There is no coordinate system other than the machine coordinate system for OOB axes. 

The screen has DRO types that should show the machine position of the OOB axes.  Also there is a DRO types to show the counts and velocity of the motor as well. 

However, one could track the position of the motor with a script variable.  Home it first.  This is position 0.  Then track all moves (adding to the variable for incremental or explicitly setting the position for absolute). 

Steve
Re: Out-Of-Band Axes in Hobby vs Indusrial
« Reply #18 on: May 11, 2018, 04:19:34 PM »
Okay.  I just figured out the homing.  That wasn't too bad. I just need to add the RC in there so I'm not assuming anything in my code.

I did figure out that the DRO could read the OOB Axis position.  I also got the mc.MotorGetPos to work, I was looking at the wrong motor.  It returned 20,000 counts for a move of 1 unit, of course this will obviously change when I get the motor calibrated to the tool carousel, but for now, I just did the math to get the position, I will throw that into a register for Mach and the PLC to use.  That should work just fine.  

I'm going to do some more testing with this and get my PLC and Mach changing the OB Axis position to make sure that it will do what I want.   Is this still considered Hobby??? lol
« Last Edit: May 11, 2018, 04:22:15 PM by Cbyrdtopper »
Chad Byrd
Re: Out-Of-Band Axes in Hobby vs Indusrial
« Reply #19 on: May 11, 2018, 04:33:25 PM »
Hi Chad,
where did you find:

Quote
I've got it to move using the mc.mcJogAbsStart

I cant find mcJogAbsStart in the API.chm.

Craig
My wife left with my best friend...
     and I miss him!