How to enable EPP on PCI parallel port card
- wackopacko
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I have been able to figure out which port it is on the address but I am unsure how to turn on EPP. I know the port is right since I can turn charge pump off on the G540 and I can move the motors. But the db25 is obviously not getting the charge pump signal as when I turn charge pump back on the G540, it doesnt get out of fault mode.
I guess I just dont know where to start in terms of turning EPP mode on, on ubuntu, with my PCI parallel port card.
Thanks in advance.
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dmesg|grep parport
from a terminal to see what you have.
Rick G
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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
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- wackopacko
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The command dmesg|grep parport indicates the PCI port is running on ECP mode. Is there a way to change this?
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?
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. I also used the same pin setting as with something that worked before. I believe it should be pin 16 for charge pump.
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.
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?
Also, isnt EPP mode just better anyway than ECP?
Thanks in advanced
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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.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?
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)
The BIOS only enables EPP, it doesn't necessarily set the mode.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.
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)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.
Have you accidentally added the charge pump to the servo thread? (If you do that, you will only get 500Hz)
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.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?
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.
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.Also, isnt EPP mode just better anyway than ECP?
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You just need to get the right charge pump signal (10 KHz?) on the right pin (16) and you should be good
This does require a 20 KHz+base thread
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CHARGE PUMP: The G540 is equipped with a charge pump (watchdog timer) that disables the drive without a 10 kHz signal on pin 16 of the DB25 port. You can enable this by reversing what was done in
STEP 3 and making sure that your parallel port is set to EPP mode. To do this, go into BIOS and set your parallel port to either “EPP” or “Send/Receive”; most parallel cards are set to ECP or “Send Only” by default.
Perhaps not true?
Maybe not true with emc?
But it does give the impression you need EPP for the charge pump.
You of course could run without a charge pump but it is a good safety feature if you can use it.
A cable that works with a printer may not in fact have all the connections you need for emc, but you can test it with a meter and or the parallel port tester.
Rick G
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IEEE 1284 parallel port modes are:
SPP (old unidirectional)
Bi-Directional (PS2)
EPP
ECP
Seems _very_ unlikely that EPP is needed for the charge pump especially since the charge pump is connected to a signal (pin 16 = /INIT) that the EPP state machine has no control over, and in fact
the state of the /INIT pin is just a set by a control register bit in SPP, Bidirectional, and EPP mode
Have you checked to see that the charge pump signal is there? Your troubles may be that the G540 needs too much source drive (parallel ports sink current better than source) on its charge pump signal
for the port to actually source (especially a 3.3V PCI card)
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- wackopacko
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So one of the ways for EPP to be enabled in Mach 3 or even EMC2 will be if the software requests it to switch modes? Maybe one can write a script to switch mode?
I do know that on my motherboard parport where I can turn EPP on, I can get chargepump to work.
On my PCI parport, it doesnt work even though settings are the same, only the address is mapped to the PCI card, which is in ECP mode.
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