About an older Siemens Simodrive 611

Today was a new day, i tested the ouput on the spindle drive itself and it seemed fine for the most part.. the only thing i found odd was the signals voltage... It showed an amplitude of 2.5 volts? from low state to high state...
I believe a real encoder conected directly to  the 7i77 would have 5 volt amplitude...
Will test this now.
The pictures show encoder output A on chanel 1 and output /A on chanell 2.

How would you go about changing parameters without the original control? It doesn't look like there is any way to manually do that.

The simodrive 611 is a bit old, most "parameters" are changed with resistors and potenciometers.
The drive for the spindle has a little display and you are able to Change parameters on it.

Reduced the encoder output from the spindle drive to half (2048 -> 1024) and got twice the speed... So my problem is that i AM reaching the encoder count limit of 2 MHz. 
I am Now trying to tell linuxcnc to use encoder only up to 2000 rpm and then just ignore feedback from the encoder.

You're not reaching 2 MHz with 2048 pulses/rev: max speed at that resolution would be 2000000/2048*60 > 58000 rev/min. Some problem with signal integrity perhaps?

Maybe my case can help with Simodrive 611. I had a lathe with the same driver. Personally, I think that the problem is not in the Mesa cards or the encoder. I did retrofit in mach3. I had the same problem when you put a little more speed (I almost died the first time) You need to look at the maximum speed that is put in simodrive (9000rpm in my case)
then I reduced the drive settings to max 4000rpm (and at 10v it really was that much..but as the analog output exceeds 5-7 v simodrive raises the max speed (which I think happens to you too) in the end I tried more cards with analog output as well as the battery at 9v the same happens so at 9v and at 10v it rises to maximum.in the end I installed a potentiometer on the analog output and manually blocked it to 5v which gave me 2000rpm enough for what I was doing on that lathe. There is a problem in Simodrive itself. I don't understand much about pwm and other things, but Simodrive itself definitely has a problem. I sold the lathe and the new owner accepted the situation as it is. Greeting