Start 5i25 with a firmware 5i25_g540_enc

If you see the hal pins hm2_5i25.0.encoder.NN.input-a and hm2_5i25.0.encoder.NN.input-b
changing then the encoder should work (+- any hal setup issues)

I see the signal hm2 5i25.0.encoder.03.input-a on halscop, but on hal metr hm2 5i25.0.encoder.03.position, changes only occur by 0.005 and that's it. So with encoder 01 and 05. And encoder 00, 02, 04 work. The signal level for halscop from different encoders is the same. Only even encoders work

sounds like you don't have the B inputs connected

I forgot to write about B inputs. On Halmeter it is too.
C10 payments working - I start a system without 5i25 through 2 LPT with back coupling through sino-300 and everything works. I apply Hal of such system. It seems to me that there is an error in a firmware. I looked for at different forums but did not find that someone would use such firmware. But maybe I that not correctly I do that.

Are you saying that:
hm2_5i25.0.encoder.NN.input-a
and
hm2_5i25.0.encoder.NN.input-b
both change but
hm2_5i25.0.encoder.NN.count
does not?

Yes quite so. Changes but only on 0.005
It occurs on encoder 01 and encoder 03 and encoder 05
the result changes from 0 to 0.005

I suspect you have a wiring error.
I just tested the5i25_g540_enc firmware
and it works as expected

Many thanks for the help! I will look for at myself an error.
I did a firmware by the attached file.