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Hi everyone,
I have just installed EMC and linux using the BDI
cdrom image. After figuring out that I had to log in as root, and after
setting the emc.ini file to steppermod and minimilltask (it would not come out
of estop with bridgeporttask) I managed to get step signals on pin 3 (X axis) of
the parallel port. I monitored these with my digital oscope, and saw an
interesting thing. I selected manual control, and then set the x axis to
move 1 inch. My ini file had the max acceleration at 2, and I captured the
pulse train on my scope. It looked about right I guess, with the pulse
frequency accelerating to 2 khz. The strange thing was that after the
pulse train had fully accelerated, there would be a 1 khz pulse about every 8 or
so of the 2khz pulses. I don't know if this is some latency issue, or
perhaps that is when some other task is running?
I am running on an AMD K6-2 350mhz. I am
going to be using this to control a rather large Shizuoka B-3V bed mill, with
Fanuc model 0 brush DC servo motors (60V 12A) on the x and y axis, and a Fanuc
model 5 bruch DC servo motor (90V 12A) on the z axis. I am not 100%
positive, but I believe there is not a tach on these motors, just a quadrature
encoder (called a pulse coder by fanuc). I already have two Gecko G320
servo drives (take step,dir signals) which should work for the x and y, so I am
going to start with those. I would get the servo to go card, except that I
am not sure if I would be able to use analog input servo amps without a tach on
my motors, so why not just get one or two more parallel ports?
Anyway, I want to really dig into this. I
like the idea of an open source machine controller. I discovered the
(rather large) message archives, and I will try to answer most of my questions
there so as not to clog the message board with redundant newbie stuff.
When I get a bit more experience, I would like to add to the EMC knowledge base,
as I am going to need to do a few special things like controlling my 20 position
ATC on the cnc mill.
Back to the scope,
Richard
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