Where to start?

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16 Feb 2011 08:40 #7233 by gandalf69
Where to start? was created by gandalf69
OK second try:)
I have a Bridgeport Interact 1 that has a slightly defective Heidenhain controller. The XYZ servos and spindle motor and controller work OK. After reading a bit about EMC2 capabilities, I thought it might be interesting to see if it would control the BP with minor mods such as digital encoders.

I threw a new PC together and loaded the Live CD (10.04 + 2.4.6) and Ubuntu runs OK and the EMC2 configuration selector starts up OK.

I have no idea what to do next.

In a previous post (How to use EMC) it was suggested to go here:

wiki.linuxcnc.org/cgi-bin/emcinfo.pl/emcinfo.pl?Using_EMC2

The user manual (p3) says it is useful only after configuration. See Getting Started Guide or Integrator Manual.

The Getting Started Guide seems to be about steppers and not servos?

The Integrator Manual is maybe more to the point. Is this where I should start?

BTW, parallel ports are almost extinct these days. Does this spell the end for EMC?

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16 Feb 2011 11:27 #7235 by BigJohnT
Replied by BigJohnT on topic Re:Where to start?
The Integrators manual contains the info needed for one to configure EMC while you build or convert your machine. The Users manual contains the info needed to use EMC once you have a running machine. None of my machines use the parallel port...

A servo driven machine needs two "connections" to EMC, an input from EMC telling it how fast to go and the feedback to EMC about it's current position.

A common and easy to connect to is servo drives with 10vdc +- velocity inputs and encoder position feedback. I used a Mesa 5i20 + 7i33TA + 7i37TA to convert my lathe from Siemens control to EMC.

So where to start is to try and figure out what kind of drives and feedback your mill has.

John

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16 Feb 2011 11:56 #7237 by andypugh
Replied by andypugh on topic Re:Where to start?
gandalf69 wrote:

I have a Bridgeport Interact 1 that has a slightly defective Heidenhain controller. The XYZ servos and spindle motor and controller work OK. After reading a bit about EMC2 capabilities, I thought it might be interesting to see if it would control the BP with minor mods such as digital encoders.


There are several of those around that have been convered to EMC2. I was under the impression that they used stepper motors, but it sounds like yours has Servos?

I threw a new PC together and loaded the Live CD (10.04 + 2.4.6) and Ubuntu runs OK and the EMC2 configuration selector starts up OK.

I have no idea what to do next.


You could start by looking at one of the servo configs, but see later:

BTW, parallel ports are almost extinct these days. Does this spell the end for EMC?


EMC2 supports other interfaces, and I am not sure that it is a good idea to try to run a servo machine from the p-port. It can be done, but isn't optimal in any other way but cheapness.

Pico Systems do a range of motion control hardware which uses the P-Port as a communications interface, rather than as an IO device, moving voltage generation and encoder/resolver tracking into hardware:
pico-systems.com/motion.html

Mesa (www.mesanet.com) also do a similar parallel port board, the 7i43. That too handles step generation, PWM, direct motion control and a host of other options via downloadable firmwares. At $80 it is very cost-effective and has 48 pins configurable as inputs, outputs or specific functions.

Along the same lines, there are devices from Motenc (OK) and the Pluto-P (just don't)

Moving away from the parallel port there are a number of PCI card solutions. Very popular are the Mesa 5i20 and 5i23. These are basically the same as the 7i43, but with more IO ports.
Other PCI solutions include the Opto22.

Other stuff: wiki.linuxcnc.org/emcinfo.pl?EMC2_Supported_Hardware

The first thing to do is to work out what sort of motors you have (brushed? Brushless?), what type of feedback it has (Hall, encoder, resolver, tachometer?), and how much of the existing setup it is sensible to retain.

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17 Feb 2011 09:37 #7273 by gandalf69
Replied by gandalf69 on topic Re:Where to start?
BigJohnT wrote:

The Integrators manual contains the info needed for one to configure EMC while you build or convert your machine. The Users manual contains the info needed to use EMC once you have a running machine. None of my machines use the parallel port...

OK,so I should concentrate on the Integrator Manual.

A servo driven machine needs two "connections" to EMC, an input from EMC telling it how fast to go and the feedback to EMC about it's current position.

The servos have a 2 wire power input, an analog tacho output for speed feedback, and a sine wave shaft position encoder for position calculation. I expect to need to change the shaft encoders to digital.

A common and easy to connect to is servo drives with 10vdc +- velocity inputs and encoder position feedback. I used a Mesa 5i20 + 7i33TA + 7i37TA to convert my lathe from Siemens control to EMC.

OK, so you used the 5i20 instead of the parallel port.
The info (5i20man.pdf et al) seem a bit light on, no block diagrams, etc, is anymore info supplied with the board?
Or maybe I should ask whether the info supplied was sufficient for you to make all the connections without blowing it up:)

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17 Feb 2011 10:01 #7275 by gandalf69
Replied by gandalf69 on topic Re:Where to start?
andypugh wrote:

gandalf69 wrote:

I have a Bridgeport Interact 1 that has a slightly defective Heidenhain controller. The XYZ servos and spindle motor and controller work OK. After reading a bit about EMC2 capabilities, I thought it might be interesting to see if it would control the BP with minor mods such as digital encoders.

There are several of those around that have been convered to EMC2. I was under the impression that they used stepper motors, but it sounds like yours has Servos?

All Interacts had servos AFAIK.

I threw a new PC together and loaded the Live CD (10.04 + 2.4.6) and Ubuntu runs OK and the EMC2 configuration selector starts up OK.

I have no idea what to do next.

You could start by looking at one of the servo configs, but see later:

BTW, parallel ports are almost extinct these days. Does this spell the end for EMC?

EMC2 supports other interfaces, and I am not sure that it is a good idea to try to run a servo machine from the p-port. It can be done, but isn't optimal in any other way but cheapness.

Pico Systems do a range of motion control hardware which uses the P-Port as a communications interface, rather than as an IO device, moving voltage generation and encoder/resolver tracking into hardware:
pico-systems.com/motion.html

Mesa (www.mesanet.com) also do a similar parallel port board, the 7i43. That too handles step generation, PWM, direct motion control and a host of other options via downloadable firmwares. At $80 it is very cost-effective and has 48 pins configurable as inputs, outputs or specific functions.

Along the same lines, there are devices from Motenc (OK) and the Pluto-P (just don't)

Moving away from the parallel port there are a number of PCI card solutions. Very popular are the Mesa 5i20 and 5i23. These are basically the same as the 7i43, but with more IO ports.
Other PCI solutions include the Opto22.

Other stuff: wiki.linuxcnc.org/emcinfo.pl?EMC2_Supported_Hardware

The first thing to do is to work out what sort of motors you have (brushed? Brushless?), what type of feedback it has (Hall, encoder, resolver, tachometer?), and how much of the existing setup it is sensible to retain.


Thanks, I'll check out those interfaces. and the Supported h/w.

The servos are brushed, tacho, resolver? (counts per rev), the controller needs to count in order to calculate position.
Personally I think that retaining much of the old robust and reliable servos and drive electronics is a good idea, in the lower price range only the computing hardware and software has improved over the last 20 years IMHO.

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17 Feb 2011 12:20 - 17 Feb 2011 12:22 #7280 by andypugh
Replied by andypugh on topic Re:Where to start?
gandalf69 wrote:

The servos have a 2 wire power input, an analog tacho output for speed feedback, and a sine wave shaft position encoder for position calculation. I expect to need to change the shaft encoders to digital.

Not necessarily. Resolvers are actually very good feedback devices if you can get them to work. They are tough, reliable, accurate and absolute.
I am working on a way to read them with an Arduino (in fact, I ordered 10 PCBs yesterday). A better/more professional approach would be the Mesa 7i49, though I am not entirely sure how well that interfaces with EMC2 at the moment. I suspect that, with the correct firmware, it just appears as a set of absolute encoders in HAL and EMC2 is none the wiser.

Note that Pico also do a Resolver converter pico-systems.com/resolver.html

The info (5i20man.pdf et al) seem a bit light on, no block diagrams, etc, is anymore info supplied with the board?
Or maybe I should ask whether the info supplied was sufficient for you to make all the connections without blowing it up:)

The problem is that the 5i20 by itself doesn't really do very much. It only becomes useful with firmware downloaded to it, at which point it can be all sorts of different things.
The best documentation on what the 5i20 et al do with the EMC2 drivers is probably here:
www.linuxcnc.org/docview/html/drivers_hostmot2.html
Though some other capabilities are due to be released in the next revision (which is fairly imminent) and are included here:
www.linuxcnc.org/docview/devel/html/man/man9/hostmot2.9.html
Last edit: 17 Feb 2011 12:22 by andypugh.

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17 Feb 2011 13:24 #7281 by BigJohnT
Replied by BigJohnT on topic Re:Where to start?
Does the 7I49 6 channel resolver interface work with the 5i20?

John

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17 Feb 2011 14:46 #7285 by andypugh
Replied by andypugh on topic Re:Where to start?
BigJohnT wrote:

Does the 7I49 6 channel resolver interface work with the 5i20?

I don't know. That sounds like a question for Pete.

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17 Feb 2011 15:43 #7287 by PCW
Replied by PCW on topic Re:Where to start?
No, I've tried and couldn't make it fit. It will fit in the 7I43-400, 5I22, 5I23, 4i68,4I69, 7I61, 7I62 and 3X20 but not the earlier Spartan2 based cards like the 5I20 or 4I65.
I recently managed to squeeze some things in the 5I20 that would not fit before by tweaking some Xilinx compile options (6 and 8 channel sserial + servo configs) so I can try those option on the 7I49 but it think its still not likely to fit...

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17 Feb 2011 17:15 #7288 by andypugh
Replied by andypugh on topic Re:Where to start?
Does the Resolver card work with EMC2 as-is, or is a driver needed?

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