RE: [CAD_CAM_EDM_DRO] Parallel vs. Serial

About the Maxnc signal problem.
You maybe able to fix that problem by using a hex inverter to invert the
signals going to the G320s. It would be a simple fix. Use a 74hc04 or 74hc14
with the smchimtt trigger.
Derek

-----Original Message-----
From: Dan Mauch
Sent: Tuesday, November 13, 2001 11:49 AM
To: CAD_CAM_EDM_DRO@yahoogroups.com
Subject: RE: [CAD_CAM_EDM_DRO] Parallel vs. Serial


Speaking for Camtronics, I can say that I too use BOBAD/CAM ver. 17 to
generate the tool paths, all though it isn't the best cad/cam program
around, it does work.
If you have the standard Maxnc that provides phase signals then it would
not work with the G320/G340 amps because they use step and direction
signals.
If you have Maxnc step and direction software then it will work all
though I have run in to some problems with the G320 that use the common
+5. The problem isn't really with the G320 but with maxNC step and
direction pulses. On a recent test, Maxnc which uses a type of pulses
that are generally negative and go positive when stepped caused some
problems using a relatively fast pc ie 166 mhz. So to prove this I
switched to desknc for dos and verified that when Desknc were using
negative pulses the problem (easy faulting of the servo amp)would
reoccur but when I switched the config file to positive going pulses the
G320 ran perfectly. Unfortunately, the version of Maxnc that I have
doesn't have a config file that can change the pulse type. So you could
run into a problem if using a fast PC and Maxnc step and direction. I
talked with Mariss at GeckoDrive about this and he confirmed that the
opto couplers may not be fast enough with that type of pulses and with a
fast computer.
The servo systems that I currently assemble all use the parallel port
and run fine with programs like desknc for dos and cncpro. Now that
Carl(desknc) has fixed the backlash compensation problem with desknc for
windows, I will probably start using the serial port for communications
between the software and the desknc black box.
So to answer your question you can use the parallel port and can use
Maxnc if you have a slow pc like a 486-66 or <

-----Original Message-----
From: P. J. Hicks [mailto:hickspj467@...]
Sent: Tuesday, November 13, 2001 9:58 AM
To: CAD_CAM_EDM_DRO@yahoogroups.com
Subject: [CAD_CAM_EDM_DRO] Parallel vs. Serial

Gentlemen,

I use BobCad/Cam to draw and generate G-code. I then use the Maxnc
software
to control my Maxnc fitted Sherline. The Maxnc controller is connected
to
the parallel port as I surmise from the list is quite common. I am
about to
change over to a Camtronics servo system and I notice that the
BobCad/Cam
software sends its output to a selected COM port. I also seem to
remember
that 'large' machines use the serial port for direct connection. Am I
still
in the ballgame here or will I have to go with a completely new softwre
stystem? Does the Camtronics system run through the serial port? Do I
need
intermediate software or some sort of serial to parallel converter?

Regards, PJH, N7PXY