Help wanted: MESA board selection, parallel vs ethernet and THCAD understanding.

Here is 1 option too.... which could be added to the second port.

eusurplus.com/index.php?route=product/pr..._61_60&product_id=54

more expensive than a 7i92 but offering 4x ports (that is 4x17 I/O's!):
eusurplus.com/index.php?route=product/pr...62_71&product_id=101

The mesa firmware is VERY adaptable and easy to change to your setup (need to finish off my thread on that!)

tommylight wrote:

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Encoders can be also wired to Mesa 7i92 inputs on the spare header, but not advisable as those inputs are very sensitive, so care must taken for shielding and grounding.
I use those inputs on Plasma cutters, by far the worst environment for them and they work perfectly, used as encoder counter for THCAD.

Yes, I have had made (I did the pcb design + got it shipped from china with SMT components fully assembled) an interface board using 3x 74HC04D chips.  it uses the standard LPT config (pins 10,11,12,13 and 15 input, all others output).

I have thought about getting a few more made as all input and all output options and offering them for sale.
(I am also thinking about offering pre-configured linuxcnc PCs for sale with ethernet ports set up for plug and play operation with mesa cards .... if someone gives me their setup..... not sure if they will fly though).

eusurplus.com/index.php?route=product/pr..._61_60&product_id=99

no bubbles burst,

That is a a very specific isolator for a 7I77
(so all the isolator directions match a 7I77)

Thanks Peter,

I had not looked into its purpose / details it was just when Tommy mentioned Mesa + isolation, that item sprang to mind as it was something I'd seen in passing.

The board I made was just an I/O interface to act as a buffer / input voltage clamp (and signal inverter) using 3x 74HC04 chips for the 17 i/o. very simple board, and an led on each input or output to confirm visual signal status. It was mainly to provide PWM interface with a laser diode, + 2x SPINX1 boards and a superpid in a neat interface, with a second encoder input for the superpid index. (I am sharing a 7i76e between a router mill and plasma cutter as 1 control box with shared drives, and a different config for each setup with connectors going into each device using a common wiring arrangement of connectors). In a 'perfect' world, I'd set each device up on it's own, but it's just a hobby for me, and its all in 1 oversize garage.

I may split stuff out over time into its own control boxes, now I've got a 7i92+7i76 (for the lathe), and a 7i98 for a bench device. now I've got into the firmware and see the flexibility of mesa hardware, things with linuxcnc are starting to click.

I nearly bought a 7i75 (as they are not very expensive), but thought I'd get back into designing my own PCB's and getting them manufactured (I've dabbled, started in electronics (hardware) 25 years ago) eusurplus.com/index.php?route=product/pr..._61_60&product_id=98

I thought that the 8mA per output channel was a bit low, and went with the 74HC04D with up to +/- 20mA per channel, 500mW. I wouldn't expect to be using that, it's just a nice buffer.

my circuit would NOT provide 10mhz per input channel.... but I'm just using it as an index input for a superPID (up to 30,000rpm / 500pps (Hz)). So it'll do for my needs.

anyone interested in designing PCB's and getting them manufactured, I'd suggest having a go themselves (its another tool + something to learn + understand)
easyeda.com/
jlcpcb.com/parts
jlcpcb.com/

Sorry, bit off topic.... but maybe its useful to someone.
I am 100% certain that no business is at risk of me dabbling (I have a full time job and this is just a hobby not a need, necessity or desire).
Sure you may get it wrong... but an education costs money and a good education costs good money!