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Author Topic: Hello 1st post, need advice on controller, board, drivers  (Read 18740 times)

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Re: Hello 1st post, need advice on controller, board, drivers
« Reply #30 on: April 16, 2008, 09:49:19 PM »
I think that a variable square wave is a far cry from step and direction.
Sort of like a PWM signal.   Where equal high/low is no movement, 50 to 100% High is FWD and 50 to 100% Low is REV.
Just a guess,
RC
« Last Edit: April 16, 2008, 10:00:07 PM by Overloaded »

Offline Hood

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Re: Hello 1st post, need advice on controller, board, drivers
« Reply #31 on: April 17, 2008, 02:19:38 AM »
The guy obviously doesnt know that servo drives can also be controlled with Step/Dir signals, Also he says the motors take the square wave, thats crap, the motors will take a DC voltage and the polarity will be reversed for direction change. The drives however will take the square wave so at least you are getting some decent info. LOL
 Anyway it sounds more like CW/CCW signals rather than Step/Dir but even then it desnt sound quite right. Do you have a scope? if so try and find out the pins on the drives that accept the signals from the computer and look at them to see what is happening when jogging back and forward.
Hood

Offline NJC

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Re: Hello 1st post, need advice on controller, board, drivers
« Reply #32 on: April 17, 2008, 03:26:23 PM »
OK, did some testing, unfortunately I don't have a scope. In the motor/driver housing I have a bundle of 4 wires, 2 wires from the motor going into the driver, also I have a constant power line and a neutral going to the driver from the control panel. The power going into the driver seems to be 120 VAC, the 2 wires going to the motor from the driver are 60VDC or 40VDC, depending on the direction its moving, they swap voltage depending on the direction.

I have several wires in a seperate bundle coming from the control panel to the driver, 1 is a constant 5 volt, 1 is a constant grond, two of the wires are either 3.15 VDC or 1.75 VDC depending on which direction I enter in the controller. The other wires don't seem to be affected by movement, basically no voltage, maybe these are from the encoder?

The driver seems to act like a relay or I should say a few relays, with some sort of voltage converter for the motor, does this sound correct?

I think, if I'm correct that most systems are powered with 5VDC, if that's the case, and with the voltage that I listed above, can this be wired easily?

Scott

 

Offline Hood

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Re: Hello 1st post, need advice on controller, board, drivers
« Reply #33 on: April 17, 2008, 03:41:42 PM »
OK first thing I would say is your drive is definitely taking digital signals rather than analogue, this ties in with what the guy said regarding the pulses. Your DC to the motor should change as speed increases,  ie get higher for faster and lower for slower. Also the polarity should reverse as rotation reverses.
 The wires that you are not seeing a voltage on may be the pulse wires, try setting your meter to mV range and see if you get anything, if you do does it increase with speed?
Really a scope is needed to see exactly what signals are coming from the computer to the drive, dont suppose you know anyone at a college or school that could borrow one? preferably a dual trace.

 If your drives are CW/CCW pulse input then it may be possible for you to use them. Also have a look on the drive where all of the wires go in and see if there are any markings, also on any of the terminals that dont have wires connected, if there are such terminals.
Hood

Offline kcrouch

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Re: Hello 1st post, need advice on controller, board, drivers
« Reply #34 on: April 17, 2008, 04:23:35 PM »
Need to jump in here.
Your drives/amps are located in the motor housings. Input to the drives is definitely pwm and not step/direction. feedback is through the separate encoder signals.
You'll need a driver that interfaces with Mach and generates PWM output to the servo drives. I am not sure who makes one, but I will look and report back here.
You can NOT use step and direction to run these drives.
Sorry for the bad news, But I'll keep looking for a solution.
Kenny
Having way too much fun! Something must surely be wrong.

Offline kcrouch

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Re: Hello 1st post, need advice on controller, board, drivers
« Reply #35 on: April 17, 2008, 04:33:22 PM »
I'm back!
Check here, they may be able to help.   http://pico-systems.com/pwmbox.html

Kenny
Having way too much fun! Something must surely be wrong.

Offline Hood

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Re: Hello 1st post, need advice on controller, board, drivers
« Reply #36 on: April 17, 2008, 05:09:39 PM »
Great info Kenny, are you familiar with these kind of drives?

Hood

Offline NJC

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Re: Hello 1st post, need advice on controller, board, drivers
« Reply #37 on: April 17, 2008, 09:36:33 PM »
Kenny, are you farmiliar with the prototrak system? So is what you are saying that I will be keeping the servo drives and servos that I have and adding a controller and driver between Mach and the servo drives? Sounds like I'm in need of a translator :D What is pwm by the way? Would I need the entire control box with controller, drivers and power supply, or just the drivers? If I got the entire box, would I then be connecting the output of the "smoothstepper" directly to this unit? That would be simple.

Hood, didn't you say in an earlier post that you are using picos? If so, can you tell me a little more about your set up?

Scott

Offline kcrouch

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Re: Hello 1st post, need advice on controller, board, drivers
« Reply #38 on: April 17, 2008, 09:54:03 PM »
Scott,
Yes, I am familiar with the Prototrak system. You'll need a controller like the Pico to hook to Your existing drives. I need to confirm the connections with one of my customer's machines. I will try to do that tomorrow. If I am successful, I will try and give You connections to the Pico. The Pico was developed for the EMC software which is very similar to Mach3. I have been following this thread, but want to be sure before leading You off in a direction. You would be using the Pico instead of the SmoothStepper, unless of course, they implement some type of PWM output. You should probably contact them and ask about that directly. If so, please forward their response to me and I'll have a go at the connections for You.
Kenny
Having way too much fun! Something must surely be wrong.

Offline NJC

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Re: Hello 1st post, need advice on controller, board, drivers
« Reply #39 on: April 17, 2008, 10:14:57 PM »
You are the man! I will email the guys at warp9 and find out about the pwm output
Scott