How to enable EPP on PCI parallel port card

Does your parallel port cable have all the pins brought out? Some do not have all the pins connected,

Why does the charge pump require EPP? AFAIK all you need to do is load the charge pump component and connect it to the correct pin on your parallel port. Some googling suggests that the EPP is a winsnows need not EMC.

wiki.linuxcnc.org/cgi-bin/emcinfo.pl?About_Charge_Pumps

John

wackopacko wrote:

Regarding the link www.pmdx.com/2PARPCI, are you suggesting in general PCI cards dont play well with things requiring EPP such as gecko drives? Or that I should essentially buy another card?

The card you have should be fine with the G540, which is just a normal step/dir drive. EPP is only useful when sending data from the parport in binary format. You are not doing that.
Also, as an aside, it probably makes no sense at all to buy a Parport card to run a G540. Mesa have just brought out the 5i25 which is like a parport on steroids, that does all the step generation and suchlike on the card itself in hardware, so you can step at MHz rates. It costs $89, which is quite a lot more than a parport card, but then it does a ton more stuff too. (You can, for example, add a second DB25 header and connect 96 more IO pins on daughter-cards)

I think all the pins are brought out. I have not changed the cabling, and its the same cabling that works on a computer with a motherboard parallel port that was definately in EPP mode as set by the BIOS of said computer.

The BIOS only enables EPP, it doesn't necessarily set the mode.

I am not sure if charge pump requires EPP or that gecko requires EPP, but it does state specifically in the manual it needs EPP to run, I do think I have the charge pump pin set correctly in stepconfig/.hal.

What is your base thread period? The G540 needs 10kHz. and to get that the base thread period needs to be <50,000nS (it would be very unusual for it not to be, though)
Have you accidentally added the charge pump to the servo thread? (If you do that, you will only get 500Hz)

So do you mean I can safety use the g540 without using charge pump at all? I am able to make the motors move without using charge pump (the g540 has a toggle at the back so you can switch it off), but I dont know if that is the preferred configuration since the manual seems to suggest they want it, and I dont want to run into issues were the steppers miss steps or something? So is it ok to go without charge pump?

Charge pump is a safety device. It means that if the control PC crashes or freezes, then the cyclic charge-pump signal stops, and the G540 shuts down.
It isn't all that critical with a stepper device, because if the PC crashes, then the steps stop coming too. But it's a good thing to have, really.

Also, isnt EPP mode just better anyway than ECP?

No, not really. It is more complicated, and less tightly specified, so there are cards out there that do EPP in different ways, so that not all EPP hardware works with all EPP ports. It's something to keep away from unless you actually need it.