5i25 + 7i85s +....

Indeed the VFD has a reference source signal

Definitely i will use the SPINX1 to control the spindle.

Now i would like to know how to connect it to my system. Do i have to connect it to the 7i85 or to the 5i25? Which cable do i need to do it?

In the 7i85s i have in use ENC 0, ENC 1, ENC 2 and DIF OUT 0,1 DIF OUT 2,3 DIF OUT 4,5.

But the rest of them are free, how can i use them for GPIO purposses?

Thank you.

As long as you are using LinuxCNC 2.7X, You can use the 3 ENC3 inputs for general purpose inputs (for limit switches etc)
they would need to be jumpered for TTL mode

The spare differential outputs can be use for spindle PWM and enable for example
the unused RS422 output could be used for direction

If you need more simple I/O You might consider using a 7I75 on the unused 5I25 connector

Im using 2.7 so that sounds really good!

Is there the posibility to use just one input for the limit switches for each axis? I mean placing two limit switches per axis, but jus one input for them. If linuxcnc is going for example to +X, and this input gets ON, then linuxcnc has to know that must block the movement of +X, but not -X.

If there is something likely i think i can make all what i want with a SPINX1.

Thank you.

You can run all the limits off of one input if you like.

Linuxcnc stops all movement if a hard limit is hit, it does not restrict movement to only one direction. You have to activate the limit override to jog when a limit switch is triggered.

Linuxcnc isnt capable of detect which limit is activated in order to just let the movement in the other direction?

It is a strange thing seeing how much capable is this program.

Thank you.

Sorry i think i didnt understand Todd correctly.

How linuxcnc manage limit switches? If i had two limits per axis, with one pin for each ( a total of 6 limitis with six pins ), linuxcnc would be able to stop just the direction the limit activates? dont allowing for example to move +X, but allowing moving -X.

In case that linuxcnc can do this diferentation, as i have 4 inputs, is capable linuxcnc to work with references paireds with one of the limits of the each axis? I mean having 2 limitis and one reference per axis. 1 pin per axis, and 1 pin for all the references ( a total of 3 pins for axes, and 1 for references = 4 ).

This way maybe linuxcnc is capable to know which axis and witch direction is being activated.

Thank you.

I have to partially recant my previous statement. I based my statement on observation and the fact that many people use common inputs for limits. The machines i've set up have all used independent limits, but to be honest with you I had never really tested what would happen if the machine was jogged the wrong way when a limit switch is active. I tested it on one of our machines on my way out the door and found that Linuxcnc did in fact not let me jog further into the limit (I pressed the switch by hand while the machine was in the middle of travel. When I re-powered the machine with the limit active and the override limits checked, and I tried to jog towards the limit, and an alarm message was generated, and no movement occurred.

I am not sure what the exact behavior is when using a common switch input. (I don't have a machine set up that way to try it.)

I have not noticed any documentation on this subject of exactly how Linuxcnc behaves with different configuration combinations. (that doesn't mean it isn't out there)

As i have my system ready to test it, i will try different setups and i will post the results in this week or the following.

Tahnk you all.