Troubles to get started with SD240 Retrofit

If you set x-index-enable high manually, does it get cleared if you jog the axis? 
(enough for one full turn of the encoder)

Beware, this may trigger a following error

No, it does not.
I scrolled through the HAl and could not find the hm2_7i80.0.encoder.00.input-index pin linked anywhere. So I assume Linuxcnc does not get this signal- can this be the reason?

No, the actual index pin is not typically used by LinuxCNC

What interface card are you using for the encoder interface?

Is the encoder single ended or differential?

Is  the interface card jumpered to match the encoder type?

Another way to check the low level hardware is to set the index input to
single ended mode, and then watch hm2_7i80.0.encoder.00.input-index
in halshow as you ground the index input on the interface card.
hm2_7i80.0.encoder.00.input-index  should change state when you ground
the +index input pin

(with the encoder unplugged of course)

 

I´m using a Mesa 7i33 for the encoders and pwms. The encoders are Fanuc, so there is very little info to get on the specs of the encoders. All I know is they are TTL and 2000i/rev
All I have additionally is the schematics of the control where the encoder connection can be seen:
 

As it shows inverted channels I think they are differential types
And yes, the 7i33 is jumperd to TTL (Jumpers DOWN)

That brings up a couple questions?

1. if the encoders have differential outputs, why in the 7I33 jumpered for single-ended (TTL) inputs

2. Leaving the TTL option enabled, can you check that grounding the INDEX+ input (encoder disconnected)
changes the state of the hal index pin (hm2_7i80.0.encoder.00.input-index for X)

1. if the encoders have differential outputs, why in the 7I33 jumpered for single-ended (TTL) inputs
Answer: because I was told so image missing /media/kunena/emoticons/smile.png  - I am really not ecperienced in these things and asked how to get the motors working and showed the schematics to experienced guys- and I was told how to wire the encoders and how to jumper the 7i33.2. Leaving the TTL option enabled, can you check that grounding the INDEX+ input (encoder disconnected)
changes the state of the hal index pin (hm2_7i80.0.encoder.00.input-index for X)

...ok, I will check this with disconnected encoder and report.

Thank you
Sigi