EMC2 questions

[MB300E]

Hi all, i am new to this.
I wonder what computerhardware you will need to run this, i have heard that it has to be a P4 but its hard to believ as i have been runing linux for many years and know that most computers will handle prety good with linux.

Other thing i wonder is if it is posible to use two LPT ports, like LPT1 and LPT2 at the same time?

[samco]

iirc - the slowest computer I have used with dapper drake (6.06) is a 400mhz pentium II. I am running a gantry with a 600mhz pentium III (easy 236 ipm at input scale of 2540). For the most part - faster the better as long as it has good realtime performance. You will also need atleast 256mb of ram. (maybe more for installation from the livecd)

sam

Edit - yes - you can use 2 or more printer ports at the same time.

[MB300E]

ok nice, i have looked around but havnt find anywhere where it say how many ports that can be used
its hard a litle hard to build something that can handle more then 4 axis at one port, maybe is enough with 4 axis but its nice to know that you have some ports for future projekts

[unterhaus]

there are probably still some people using pentium 1 computers. You could probably get it to work on a 486, but you'd have to be smarter than I am.
This would only be doable with servos or hardware step/dir generation, if you are trying to do software step/dir generation, you better have a PIII or faster.

[Gads]

Fairly new to this but have my 3 axis stepper system setup and running ok
on 450Mhz w/256Mb ram, ubuntu 6.06 & emc2. so far i havn't run into any problems with this setup.
I would be curious to know where problems would be seen. ? loststeps on highspeeds, large programs ?

[Ryobiguy]

EMC wakes up and is able to read/write to the pins and make various calcuations every [so many] times a second. This is set as the "Base period". I have a 900mhz P3 and I find I can go as low as 40 microseconds. If I go any lower it blows up (well, not literally of course.)

The base period as an absolute limit to the maximum output pulse rate. But, for example, if the step output frequency is around half of the base period frequency, it will be very choppy and you might lose steps. So for exampe if you need high speeds using a super microstepping drive, it would probably run smoother from a faster PC.
As far as how good is good enough? Good question, I wonder what the rule of thumb is.

[Big John T]

I have 3 parallel ports on mine, it's just a configuration where you tell it how many and where and if you want them to be input or standard. Input gets you 13 inputs and 4 outputs and standard you get 5 inputs and 12 outputs. I use a cnc4pc breakout card for each port. This gives me a place to land the wires and isolates the parallel port.

John