Advanced Search

Hi.
I have mini pc that i tried to install linuxcnc ( latest version) but horrible latency above 100000.
So i put Debian 12 and install kernal RTai 5.4.258 and linux cnc 2.9.3.
All is good, latency test is like max 24000 with default settings in the bios ( remove everything from the bios i got about 16000 after 2 hours).
The problem sometime the mini pc freeze when running tests (latency-test) so i have to restart.
I thought the bios settings was the culprit so i restore bios to default but the same.
Should i use i different distro or kernel?
 

[/attachment]  I know that there is a configuration 7c81_7i78x2d.bit, but there is the same on P2 as on P1 - 7i78. Another 4 axes. And I don't need that for the lathe. But I would like one MPG encoder for each axis - basically to be able to control the lathe "almost" manually. The rest of P2 controls the tool turret and on P7 there are limit switches and buttons.
So that's the goal.

tommylight wrote:

You would need this and maybe another DB25 to DB25 cable, also know as parallel port cable
eusurplus.com/index.php?route=product/pr...59_63&product_id=130
And might need a firmware flash, but do check what is already installed on the card using mesaflash

Basically what I meant, but better phrased.

Cheaper option from startech:
www.startech.com/en-ca/cables/plate25f16lp

I have an extra DB25 to DB25 (parallel port) cable (also startech actually, really old OG startech).

I didn't say it was a PATA cable, it's just a bit reminiscent of a PATA IDE cable.

I forgot about floppy drive cables!

Brings back good memories of ripping floppy drives out of old PCs.

langdons wrote:

You need a parallel port(female) to flat connector (think IDE PATA connector).

Dude, really ????
IDEA PATA is a 40 pin connector, and just to make you wonder, comes with a 40 wire and 80 wire flat cable.
Find out why.
And as a precaution, it is not a floppy drive connector either, that has ?? pins !

You would need this and maybe another DB25 to DB25 cable, also know as parallel port cable
eusurplus.com/index.php?route=product/pr...59_63&product_id=130
And might need a firmware flash, but do check what is already installed on the card using mesaflash

Yes it is possible to do that, at least from what it says on the MESA website.

You need a parallel port(female) to flat connector (think IDE PATA connector).

(Or, more like likely, an IDC 26 (male) --> DB-25(male) | DB-25 (female) --> DB-25 (female) | 7i78)

I think this is one such cable:
store.mesanet.com/index.php?route=produc...oduct&product_id=315

I think I have such an extra such cable, I suppose I could mail it to you or something.

How can i use a 7i96s together with a 7i78 to get 2 more STEPGENs?

My main board 7i96s was being used to control 5 axis Stepgens, but one has fried completely, and i was hoping i could expand the board with a 7i78 i have laying around, to control a total of 6 (4+2) stepgens. is this possible? What bit file should I use? Is there one available for it ?


Best regards
 

There is a 7I78X2 configuration: 7c81_7i78x2d.bit 

Do you need MPG encoders or high speed encoders+index?

Hmm...

I don't think VFDs really lose that much torque at low speeds.

Maybe at really low speeds they might, but you should be fine.

However, with a gearbox, halving speed doubles torque, which is not the case with a VFD at all.

I have opened an issue:
github.com/LinuxCNC/linuxcnc/issues/3668

Alternatively, could someone please create a bitfile for me for 7c81 with one 7i78 and port P2 entirely for encoders (i.e. at least 3)?

cmorley wrote:

This should be moved to the Qtvcp section..

Done.
Thank you.

I've never moved anything in a forum before, how do I do that?

This should be moved to the Qtvcp section.
Looks promising! Keep is updated! If you get stumped with the programming i can try to help.