Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: epineh on March 11, 2008, 09:14:43 AM

Title: Will Mach Output Quadrature ?
Post by: epineh on March 11, 2008, 09:14:43 AM

Hi all, I am building a servo system and the drive I am using (DSPIC) uses quadrature (CW - CCW) for the input instead of step/dir.

I can change the step/dir to quadrature with logic but I was wondering if Mach will support this outright ?

From what I understand quadrature is faster than step/dir as it can be written to the port in one cycle instead of two.

I posted this exact question over on CNCZone but have not had any replies yet, so I thought I would ask here :)

Cheers.

Russell.

Title: Re: Will Mach Output Quadrature ?
Post by: Hood on March 11, 2008, 07:13:55 PM

No Mach can only output Step/Dir as far as I am aware. Will check with Brian and if the answer is different then I will let you know but dont think it will be.
 Can your drives not be configured to accept Step/dir without having to resort to logic?

Hood

Title: Re: Will Mach Output Quadrature ?
Post by: epineh on March 11, 2008, 11:40:46 PM

Cheers Hood, I had a feeling that would be the case.

To accept step/dir the source code would have to be modified, at this stage a couple of logic chips would be the easier option for me (little rusty on my coding) and I make my own boards so a few changes/additions on a layout isn't a problem.

Thanks.

Russell.

Title: Re: Will Mach Output Quadrature ?
Post by: Chip on March 12, 2008, 02:51:59 AM

Hi, Russell

Just maybe one of the "Max NC Wave Drive" may use rollover 2 pin output's , it would do your a,b - a,b then b,a - b,a the other way.

Check it out, I think you don't have a choice of pin number selection though.

Mite do It, Chip

Title: Re: Will Mach Output Quadrature ?
Post by: HillBilly on March 12, 2008, 07:42:43 PM

What you what is MaxNC CL mode. But you are locked in to the output pin assignment.

PIN ASSIGNMENTS FOR THE
MAXNC CL2 SOFTWARE

PRINTER PORT PIN ASSIGNMENT

1............... M3 OUTPUT (LOW=ON, PULSE FOR PWM)
2............... A AXIS (quadrature)
3............... A AXIS (quadrature)
4............... Y AXIS (quadrature)
5............... Y AXIS (quadrature)
6................X AXIS (quadrature)
7............... X AXIS (quadrature)
8............... Z AXIS (quadrature)
9............... Z AXIS (quadrature)
10.............. INPUT, MOVE ENABLE (LOW=NORMAL OPERATION, HIGH=STOP, SEE NOTE)
11.............. INACTIVE
12.............. INPUT, HOME SWITCH (NORMAL OPERATION LOW)
13.............. INPUT, G61 SWITCH SENSOR
14.............. M8 OUTPUT (LOW=ON)
15.............. NONE
16.............. OUTPUT, DISABLE POWER TO MOTORS (LOW=NORMAL, HIGH=DISABLE)
17.............. OUTPUT, RESET CONTROLLER (LOW=RESET, HIGH=NORMAL)
18.............. ALL SIGNALS GROUND
19 TO 25 ....... NONE


NOTE: MOVE ENABLE IS USED TO STOP THE COMPUTER STREAM OF CODES UNTIL THE SERVO
MOTORS CATCH UP. ON TIME-OUT IT WILL PRODUCE A SERVO ERROR





Darek

Title: Re: Will Mach Output Quadrature ?
Post by: epineh on March 13, 2008, 04:34:32 AM

Awesome guys, the pin config is not a prob, as I will be making my own BOB as well as the servo drives.  This is good news, saves mucking around with logic :)

I am building in parts, got the H-bridge design done, populating and testing this weekend hopefully, and the micro board will be seperate, hopefully finished in a week or two.

I can post my results here if anybody would like to see the outcome.  (if it works).

Cheers.

Russell.