Testers Needed for New RTAI Packages

BeagleBrainz wrote:

The Asrock J3355 ITX boards have a parallel port

do you use that one? i cant find anybody selling one tho except for somebody on amazon marketplace, but they have a less than stellar rating.

Yep seems new egg is out of stock.
This maybe an alternative
www.newegg.com/asrock-j4005m-micro-atx/p/N82E16813157804
or this being a little cheaper
www.newegg.com/asrock-j3355m-micro-atx/p/N82E16813157730
A few more beer tokens get you quad core
www.newegg.com/asrock-j3455m-micro-atx/p/N82E16813157729


The Parallel Port is an on board header so you would need a bracket with a Parallel Port connector on cable.

I ordered mine from New Egg and had no issues with delivery.

Although for a similar price (or little more) you can get a Mesa 7i96 store.mesanet.com/index.php?route=produc...oduct&product_id=311
And when it's time to replace a MoBo\Computer as long as it has an Ethernet port you are good to go.

I am running that duel parallel port SIIG card using the Linuxcnc Stretch Preempt-RT ISO, on an older HP Pro 3400 series MT, i5 machine I pulled from our IT guys scrap pile at work.
lspci -v shows this for the card.
and the addresses I use in the hal file are 0xe010 and 0xe030.

Todd wrote:

I am running that duel parallel port SIIG card using the Linuxcnc Stretch Preempt-RT ISO, on an older HP Pro 3400 series MT, i5 machine I pulled from our IT guys scrap pile at work.

i have almost that exact setup on my primary machine, except i am running two manhattan parallel ports (MosChip 9865) and its an full atx asus board. the numbers are rock solid with stretch using isolcpus and it can maintain a latency of around 1.8k no matter what. the down fall is that its a friggin beast! this thing reminds me of the old beige box days when your tower was exactly that: a tower. stephen king wrote about it and sauron lived in it.

ironically enough, when i installed the rtai kernel on it, my numbers went through the roof, but on another box running an athlon 64x2, it cut my latency by a factor of 10. that was the first time i ever seen sub 1k latency.

BeagleBrainz wrote:

www.newegg.com/asrock-j4005m-micro-atx/p/N82E16813157804
or this being a little cheaper
www.newegg.com/asrock-j3355m-micro-atx/p/N82E16813157730
A few more beer tokens get you quad core
www.newegg.com/asrock-j3455m-micro-atx/p/N82E16813157729

those actually look pretty promising. i thought that intel integrated graphics caused problems tho. also i couldnt find anything that stated what voltage the parallel header was running at.

BeagleBrainz wrote:

Although for a similar price (or little more) you can get a Mesa 7i96 store.mesanet.com/index.php?route=produc...oduct&product_id=311
And when it's time to replace a MoBo\Computer as long as it has an Ethernet port you are good to go.

so i have pretty much came to the conclusion that even with rtai, it looks like software stepping is for all intents and purposes a dead end and for what i am doing i really need to go to hardware stepping.

i have been looking at one of these for a while, but i wasn't sure what to get. originally, i was thinking 7i76-6i25, but i would need it eventually 4x. i was also looking at the 7i96, bu i think i am missing something here. is it stand alone and just uses ethernet port? that almost sounds too good to be true at a buck apiece. whats the catch? especially if all i need is just a micro itx board with ethernet. i have a few of them lying around and never used them because they only had one pcie slot.

EDIT:
hey does this mean you can run one of these bad boys on a pi? the pi3 was decent, but the pi4 is a stout little piece of hardware and better yet theres the odroid xu4

Initially I was just going to use a 7i92, then I got a 7i76 to hang off it, then also got 7i73 to play with. Way over kill but I can get a bit carried away.
The Mesa kit is great, just spend some time searching the forums and taking care when hooking stuff up, don’t rush in and hook everything up at once, and it’s a piece of cake. Even a Luddite like me got it going first go, tho I did spend a bit of time playing with the boards using halrun to get a feel.
There’s a great set of wiring diagrams put together by one of the forum members floating around somewhere, maybe one of The Big Boys knows where it’s hiding

actually i should have been more clear. i have 4 machines and 3 boxes. my laser and small router share a box with the best performance and i switch them using a 4 port parallel switch that i had to gut and resolder because it came with a male port for the input. the laser requires stupid speeds for raster engraving and it sits on the same table as my small router. everything else is too isolated to share and i once tried to do that with my 2m router using a 10ft parallel cable, but the cable got damaged from walking over it even with a cable cover, and you know how hard it is to jog and position accurately when your screen is facing one way and the machine is behind you? not gonna lie, not a fan.

the reason i am using dual parports is mainly the inputs. the most i need for any machine is xyyz, 4 home switches, estop, probe, spindle pwm out, and 3 relays for spindle enable, pump, and cooling fans. the other two machines are similar variants of that config with my big router being only on/off with no cooling and the laser has cooling, but is a gantry using magic-z to control the laser pulses. the last one is a lathe, but it is still a work in progress (but seriously the hardest one to figure out!)

BeagleBrainz wrote:

Initially I was just going to use a 7i92, then I got a 7i76 to hang off it, then also got 7i73 to play with. Way over kill but I can get a bit carried away.

you are so talking to the king of carried away! story of my life -- did you not see the part about having 4 machines? that is not even including other small ones i have built that are controlled by microprocessors or are currently in the design process and 3d printers etc...

BeagleBrainz wrote:

The Mesa kit is great, just spend some time searching the forums and taking care when hooking stuff up, don’t rush in and hook everything up at once

that is what i usually do. i will set up a non production box, and get it working before i go balls out and start using it.

so here comes the obligatory gratuitous stupid question:

i think i am missing something very important here because this just seems WAAAAAAYYYY to simple. the 7i76 is just a single board that communicates with lcnc via ethernet. i assume there is a mesa comp that is called the hal that sends the packets out instead of the parport comp and this board handles the rest. plug it into your ethernet, power it up, hook up your drivers, encoders, endstops etc to it and thats it. well short version anyway. no other boards, no daughter boards, not other interfaces. and we are talking steppers here, not servos (im not that fancy yet) and open loop. my steppers are dual shaft and i eventually will invest in some encoders to close the loop, but one thing at a time. all this for a pinch over 100us.

sorry, but that just seems way too easy and im waiting for the hammer to drop.

Not the 7i76 but the 7i76e

Yep it is that simple, the FPGA on the Mesa card generates the timing signals for the steppers and other such magic in hardware, I think there is a softcore cpu , that performs some other fucntions. From what I can gather that description is gross oversimplification. Just think of it as a "Blackbox".

JT's store has a great graphic via a "directory tree" graphic:
Ethernet eco system:
mesaus.com/ethernet-cnc-solutions/

PCI & PCIe eco system
mesaus.com/pci-and-pcie-solutions/

Note there is some overlap with the the daughter boards.