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Author Topic: step-analog board,CNT 803  (Read 9547 times)

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Offline comet

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step-analog board,CNT 803
« on: January 08, 2009, 05:34:50 AM »
Hi,
  What is the curant state of play with available step-analog conveters?
I have found these,but they are quite expensive:

http://www.vigproducts.com/html/an2step.htm

 Also while Im here does anybody have any information on the Ctek CNT Controller?
I cant get any information out of the manufacturers regarding the servo drives.
I am thinking of retro fitting to Mach3
   Hope someone can help
   Tony

Offline Hood

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Re: step-analog board,CNT 803
« Reply #1 on: January 08, 2009, 06:02:38 AM »
Rutex do the R2040 but dont know anyone that has one. You seemingly also need the motherboard from them and then encoder boards as well, all in all the cost is around $400 from rutex for 3 axis.
Hood

Offline Chip

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Re: step-analog board,CNT 803
« Reply #2 on: January 08, 2009, 11:30:00 AM »
Hi, Tony & Hood

I used the previous ver of Rutex step to analog board on our 4 axis water-jet cutter with no Issues at All.

Didn't need to use there encoder adapter boards in our conversion, The only issue with any of the boards out there is if you need the Index pulse.

None of them have this as an option, But you can deal with this in your Homing routine with a few logic IC's.

The board you mentioned above appears to be analog to step and not step to analog.

Hope this Helps, Chip.

Offline comet

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Re: step-analog board,CNT 803
« Reply #3 on: January 10, 2009, 04:26:32 AM »
Chip,
  thanks for that,can you elaborate on the index pulse?
I am still a bit fuzzy with resolvers,etc. as I have only dealt with simple gecko 340 systems.


cheers
   Tony

Offline Hood

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Re: step-analog board,CNT 803
« Reply #4 on: January 10, 2009, 08:11:56 AM »
The Index pulse is a feature of most encoders, it is a single pulse per revolution. Often in industrial CNC the index pulse is used in conjunction with a switch to give very accurate homing, the servo drives I use have that feature built in. What happens is when I tell the drive to home it will move the axis until it sees the switch and then it will seek out the index pulse and depending on how things are set up it will either stop there, move a certain amount of endcoder pulses etc etc.
 Another use of the index pulse would be if the motor in question is being used as a spindle, the index is then used to give the speed to Mach, however unless you are using a SmoothStepper or similar the index pulse is too short for Mach to see through the parallel port so it is no use. You can lengthen the pulse with electronics to make it usable through the parallel port though.

You mention resolvers, if you have these on your motors then afraid they are no use for Mach, you will have two choices, get a resolver to ttl convertor or just fit an encoder inplace of the resolver (or as well as it)

Hood

Offline comet

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Re: step-analog board,CNT 803
« Reply #5 on: January 10, 2009, 12:24:26 PM »
Hood,
   chers thats very informative.
Resolvers is another ofthose things I have heard mention but I dont know what they are and how they
interface with encoders? Can you advise on any books or websites I could read?
  cheers
       Tony

Offline Chip

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Re: step-analog board,CNT 803
« Reply #6 on: January 10, 2009, 12:55:04 PM »
Hi, Tony

"Hood", explained it pretty well, Encoders for general use (Lower Priced) generally don't have Index pulse output (or An Option when ordering).

When converting a Higher End analog + - servo system over to step & direction, It's just something you may/may-not need to consider.

Hope this Helps, Chip

Offline Hood

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Re: step-analog board,CNT 803
« Reply #7 on: January 10, 2009, 02:02:35 PM »
comet
 The people you first linked to have a pretty good description of resolvers on their resolver to encoder converter page.
http://www.vigproducts.com/html/resolver_to_encoder_converter.htm

Hood