7i80 and 7i77

If you have a complex configuration (and 2 7I76s +2 7I77s is complex) there may be more than 8 sserial channels
so additional sserial ports are added. To enable the additional ports you need a sserial_port_N=option where N is 1,2, or 3

You can see what sserial ports are connected to which FPGA card I/O connector with the pinout list from mesaflash

All of the sserial remote manuals (like the 7I77 manual) have a complete description of the sserial protocol
including the drivers remote process data discovery method

Only driver writers care about strides (or the low level sserial protocol details)

Normally all a user needs to care about about are the HAL pins and parameters and sserial modes

You dont need to _play_ with modes, you just _set_ them to a valid value for the remote
in the config string. The sserial remote manuals have descriptions of each supported mode.

Hey, I'm exploring my options and this seemed like the appropriate thread. Does the discussion here also apply to the Mesa 7i76E?

If I'm looking to run a step/dir mill 1-2 months from now would you recommend going with the 5i25+7i76 or is the 7i76E also an option? I'd prefer to go with Ethernet since it seems cleaner, but if that means giving up the configuration wizard and exploring uncharted territory I might stick with PCI for a while.

You should be able to take a pncconf generated 5i25/7i76 config and with very minor editing,
turn it into a 7i76e config (or 7i92/7i76 config)


Getting the Ethernet cards going will be easier once LinuxCNC 2.7 is released

I have the 7i76E and it runs ok, but the installation of the LCNC version is complicated.
If you don't need more than the IO Pins and Step/dir outputs of the board, its easier to buy 5(6)i25 and 7i76

franco_uy wrote:
what do i do with the
Warning: sserial remote device 7i77 channel 1 has old firmware that should be updated

For the moment, ignore it.

I would fix it before you run a real machine


www.mesanet.com/software/parallel/sserial.zip
has the firmware and scripts to do the update

(you might need to edit a script for the 7I80--7i77)

Hi guys many thanks for your help

, now I have both cards running OK ...
so I begun to handwrite some hal files to learn... step by step.

some days ago I managed to got succesful encoder readings and position control ok
Then I found the way to add jogging controlled by a wireless joypad.. that was cool !
and tweaked a component to make the response logarithmic..
that was super cool !


now I'm trying to make a stepper work (using a gecko G251) (yes using the 7i77) (because it's the only breakout i have so far..) via the IOs
I already have some io signals scaled down to 3.8V for dir and step so as to drive the G251 inputs
but i'm still not pleased with the results
Motor is moving but I'm having trouble with something because i get some inconsistent behaviour (pulse frequency) on output at different speeds...
i'm not asking for help here (yet ) because i still have some tests to do to find out where the problem(s) can be... and there's a chance that can be in the electronics (ie my "0" signal level is 0.8V so that might be a reason...)
anyway while i do some other tests

I fire you this other 2 questions that your opinion will be very helpful

1) after making the stepper work I'm planning to implement a closed loop schema with a servo.... I have here a gecko 320 wich can be commanded by step an dir signals, and also have the brushed dc motor with an encoder i used to succesfully test the encoder via the 7i77 last week
the questions are... a) I'm too insane to try that schema ? (yes, again with the 7i77 ! haha )
b) someone tried this before and you might have an example or maybe a link to someone else who had traveled that road before.
I know that the way to go with dcs with encoders is by using an adequate amplifier (ie controlled by the +-10V signals from the 7i77) , but I don't have one yet (maybe you can give me some advice on options there !). for example the first motors I want to move are rated 25V 85W (then I will want to try bigger motors with VFDs (i already have an ABB driving a 3HP motor and Im exited to test that too) but that will be another chapter...)
but since i already have those geckos 320 i thought it might worrth give them a try to start

besides this is my second question and the most important because i have't a clue...is this one
Q2)
I want to implement a 4th rotary axis, to work in automatic sync (toggled with a button...) with the tangent of the curve followed by ie two other axis.. say X and Y
I begun to check on the many components here linuxcnc.org/docs/html/man/man9/ and saw (just a hunch) linuxcnc.org/docs/html/man/man9/encoder_ratio.9.html.
also checked on ways to derivate ...
but im sure Im not the first trying to do this so may be you can give me some clues or an example on how to implement that whith the mesas i have
I already have waiting this crazy device I made to be driven by this rotary axis...
i promise to send you some pics

















in parallel I begun to study how to implement a closed loop configuration wth a brushed dc motor which i pretend to drive using a gecko g320..
... and I was wandering if it could be hard stuff and a not much sense excerise... but unless you tell me this is full nosnse, I will try .... (after I get the stepper working decently )

but anyway, what i wanted to ask is related to tunning of the PID... I read a procedure somwhere that starts zeroing the I and D then adjusting P till oscillation, then reduce about a half... and so on... (sure I will try this first) but que question is
what type of algorithm is implemented in the LCNC internal PID handler. read from here (blog.opticontrols.com/archives/124) is it an interactive, non interactive or parallel ?

Many Thanks Andy.
Your explanation (very clear !!) on the steps topic is totally coherent with the shymptoms I'm getting, I was aware of the granularity issue but did'n thought about the need to be careful to change speed at a pace the system can handle.

Related to using the post processor (im a complete newie on that). Seems quite straightforward.
You think perl could be a good option to do the proc. (Ive just discovered how to use it to automatically generate g-code and that has been very useful for me !! )
I guess this could be a common post processor app, and may be perl is a good option too
Is there any place where to look for this kind of algorithms already made ?
I also guess that would be interesting even to take a look at lists of post processors already made as a way to get ideas of thins that can be done at that stage

btw, interesting the app of plasma kerf correction !

many thanks !

Solved the issues related to sofwtare stepgens, I guess I have to return to the point I was originally...
trying to configure the 7i80 to generate steps/dir signals via the FPGA using the 7i77/7i76 firmware. remember ?

so. since I already have the 7i80-7i77 boards working ok I wonder (#1) how i can make it work just in the same arrangement but with the dual firmware (2 7i76 - 2 7i77), nevertheless only with the 7i77 breakout attached
(Assuming that's the way i can configure the 7i80 to load the stepgen component)

then I hope i can configure the signaling to link the stepgen outputs to the 7i77 io pins...
I should be able to do that right ?

if this is possible, can you help me with this (#1)
tnks !