AMT102 Encoder Mesa 5i25 & 7I75 (or not ) makes me crazy

Attach the voltmeter to the index signal and very slowly turn the spindle by hand, it should show at a single narrow place nearly full encoder supply voltage, in your case over 4V.

tommylight wrote: Attach the voltmeter to the index signal and very slowly turn the spindle by hand, it should show at a single narrow place nearly full encoder supply voltage, in your case over 4V.

I was wondering if the encoder outputs a fixed-length pulse at the index position, but the datasheet says not.

You mention an interface board, is that possibly capacitatively coupling the index?

The real way to test the index is to set index-enable to high then see if the hardware sends it to low.

Hi ,
i use an 7i75 board on the inner Mesa Plug.
I also use my own Binary at the mesa. But today i found out a strange thing.
I set the AT102 to 192 per Revolution this gives me an index i can see .
When i turn the Wheel slowly iA and B do their thing good then at one position the index shows 4,2 volts very short time compared to A and B very short but ok.
And it even shows it at the hal pin.
Now this only works when i use a very short cable i checked 2 cables which are around 2-3 meters long
and one cable may be bad (initial error maybe ) but 2nd cable shows maximum 1.5 v at index A and B are doing their thing.

If i then try G33.1 it never fires the index.

Now not being perfect in electronic can it be that 2 meters drop the voltage so much that i never get an Index ? I use an standard Twisted pair shielded patch cable for that
,.. any idea ?
thomas

tkamsker wrote: ,.. any idea ?

Is the encoder output differential? Is the LinuxCNC input differential?

So today i went an bought an Oszilloscope ,..
It is clear we have an Wide A and B signal (which i can see at Linuxcnc ) but the widen of the Index signal is very narrow i would say ( and for sure not like mentioned here www.cui.com/product/resource/amt10-v.pdf )
But now my question my standard speed is maximum 4000RPM (or max 6000RPM) average will be around 1900rpm
my intended PPR setting would be 192 (or 512) so do you think it makes sense to use an Condensator to widen the Index signal ? and who can calulcate the size of it ?
or is it an stupid idea ?
thomas

How narrow it is at 4000 rpm? If it is long enough for the Mesa card to see, it is long enough.