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

Since weeks i now fight an issue which i had already overcome but the source file is gone.

It is about spindle feedback done by an AMT102 encoder which goes to an extension of 5i25 board (first version was just the 26 Pin cable in an small pcb and to the encoder ) now at another machine this didn't work anymore so i tried it using an 7i75 card.

Now the A and B signals work perfect but the Index signal is not triggering so rigid tapping isn't working.
I try to measure the Index signal with the voltmeter i can't but if i use The Herz function of my multimeter i get an signal. It is exactele like the Spindle ,..
can it be that the Index is too short ?
or that the resistor and condensator at the board is blocking it ?
how do i overcome it ?
i am doing my own binary file so maybe i can adjust the length of the signal there ?
And maybe the encoder software doesn't like the Signal to be ON maybe it needs to be inverted.

any hint would be appreciated. thx thomas
And the relevant Part on the Hal file
# ---Encoder feedback signals/setup---
#
setp hm2_5i25.0.encoder.00.counter-mode 0
setp hm2_5i25.0.encoder.00.filter 1
setp hm2_5i25.0.encoder.00.index-invert 0
setp hm2_5i25.0.encoder.00.index-mask 0
setp hm2_5i25.0.encoder.00.index-mask-invert 0
setp hm2_5i25.0.encoder.00.scale [SPINDLE_9]ENCODER_SCALE


net spindle-revs <= hm2_5i25.0.encoder.00.position
net spindle-vel-fb <= hm2_5i25.0.encoder.00.velocity => motion.spindle-speed-in

i tried also filter 0
index-invert to 1
no sign
thanks in advance

Since the 7I75 can pass 10 MHz signals its not a signal bandwidth issue (the AMT 102 cannot even generate 10 MHz signals)

can you post your complete hal file?

The AMT102 was never meant as a spindle encoder. Try running it at 100 RPM or so and see if it works. Note also that certain resolution settings have different max speeds than other resolutions. There seem to be two max speeds, however, 7500 and 15000 RPM. Probably you are not exceeding those.

Jon

hi thank you for the quick reply. The reason we use the AMT102 is space but my issue is that even if i set it to 192 or 48 and turn the encoder by hand i get A and b signal but no Index signal in Linuxcnc. When i use my multimeter in RPM mode it shows the rpm. But if i use the Voltage it doesn't show the Voltage when i turn the encoder by hand. The AMT10x Document www.cui.com/product/resource/amt10-v.pdf Figure 1 says Index Width is T=360/192 =1,875 Pulse Width = T/2 = 0,9375 Index Width = P/2 = 0,46875 this should be enough. Our spindles do 4000RPM (and with faster motor 6000rpm) so even with the 7500 we are on the save side. It might be an issue with the binary for the Mesa software .
And the worsest is i had this already working but after finally assembling and updating software it doesn't anymore
So now i don't know how to best isolate my issue. maybe i load an known binary with encoder in it and see if it works from there if not i have an electrical issue. if it works it is an software issue
any hint would help thx thomas

Hi
i thought that maybe the signal is too short for the voltmeter so i tried the herz and this shows the right signal ,..
right now i don't have an oscilloscope at hand which would be handy
So you say i need to see the index also as a small sign at the voltmeter i´ll try that thx thomas

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