Messages

51

General Mach Discussion / Re: Acu-rite Glass Scale Position-Trac Coding

« on: September 23, 2010, 11:42:20 AM »

Tweakie,

In this system (Millpwr), the glass encoders are used for the feedback loop. There are no encoders on the motor. But that function is ok. I am able to get pulses for the x and y movement.

What I would like to do is use the reference output of the glass encoder to home the axis. On this encoder, they have a reference track that has reference pulses somehow encoded such that the absolute position of the table can be determined. I thought I just had one pulse in the middle of the table that I could use as a reference for home, but instead, I have many pulses I don't know what to do with. So I need to know how to use the reference track. They call  it Position-Trac. I'm guessing that the reference pulses are somehow spaced differently along the scale so that the encoder pulses can be counted between reference pulses to determine where you are; Meaning the distance between reference pulses is different along the scale so that the count would increment by one for each reference pulse. It's just a guess and I haven't the means yet to count pulses  to see if that is true.

52

General Mach Discussion / Acu-rite Glass Scale Position-Trac Coding

« on: September 23, 2010, 12:46:12 AM »

Has anyone used an Acu-Rite glass scale with the Position-Trac feature as a positioning system on Mach 3? Position-Trac encodes the absolute position of the axis into the reference output.

53

dspMC/IP Motion Controller / Re: Buying DSPMC - Why would I need Analog Inputs?

« on: September 13, 2010, 07:13:12 PM »

Thank you John. Good notes.

54

dspMC/IP Motion Controller / Re: Buying DSPMC - Why would I need Analog Inputs?

« on: September 13, 2010, 10:31:22 AM »

Thanks Scott,

That's just what I was looking for. Some examples of uses for the analog inputs.

Much appreciated.

55

dspMC/IP Motion Controller / Buying DSPMC - Why would I need Analog Inputs?

« on: September 13, 2010, 01:30:58 AM »

I'm about to buy a DSPMC. I have a Bridgeport mill with 3 axis motors/amplifiers waiting for a controller. I plan to start with the 3 axis and may expand to 4 axis. The motors are driven by +/-10V amplifiers.

There are two DSPMC; the cheaper has no analog input and the more expensive one has 8 analog input. I don't see any reason I would need analog inputs for this application, but before I buy, I want to be sure there isn't some future feature I may want to add that would require the analog inputs.

Are there any comments on why I might want to consider getting the analog input option?

Thanks,