Configuration 7i92m_7i76x1D

I took source from Frequency drive 0-10V. It should be constant.
I've measured
S900 - U12=0,9V, Power Source (Pin1-3)=10,44V
S800 - U12=8,91V, Power Source =10,44V(not changed)

Try setting the output scale to 1000 (its set to something crazy in the ini file)

Works great with OutPUT_SCALE =1000. Thank you hundred times, Peter.

I wonder why it differs from OutPut_Scale from linuxcnc docs:
linuxcnc.org/docs/2.4/html/examples_spindle.html

There is wrong explanation.

How the output is scaled depends on the output device

The PWM example is closer to the way the 7I76 (and all sserial devices) scale outputs

Pretty sure pncconf sets this up correctly, though it might name the scaling constant a little
differently for clarity (say Full_Scale_Output instead of Output_Scale)

For a long time of work under this CNC machine, we have turned on electricity at it and and made wirst moves.
Now make configurations for machine.

Now I try to configure spindle and I've seen that spindle output of 7i76 depends of temperatre a lot.
When I configured it at first time, it was 9 of March, and it was cold, It gave me 10V, but now, when it's hot, at 100% it gives me only 80%.
MAX_OUTPUT = 4000
OUTPUT_SCALE = 4000
OUTPUT_MIN_LIMIT = 0
OUTPUT_MAX_LIMIT = 4000

May be I'm wrong, because I has some error mstakes when I start machine and turn on linuxcnc:
hm2/hm2_7i92.0: smart serial card
hm2_7i92.0.7i76.0.0 remote error = (27) Over current
hm2/hm2_7i92.0: smart serial card
hm2_7i92.0.7i76.0.0 remote error = (8) remote fault
But all axes work fine, everything OK.

Does it could be solver of this problems?

The output PWM circuit should be quite stable (it should drift no more than a fraction of a percent over 0 to 70C temperature)
I would check that the input voltage is not changing

Did the sserial errors start at the same time? the over current error may indicate an external short or a damaged output driver chip

Over current temperature error few times was blinking. After some time and restart, I don't see it any more. Also, I've inverted output GPIO outputs if step signals.

I will check input voltage but I think it's OK.
Max voltage from resistor is still 8V.

So if the supply is 10V and you get 8V out (and you have full scale in hal)
Then there is a hardware problem (damaged OP-AMP etc)

The PWM circuit is pretty simple OPTO --> CMOS gate --> passive RC filter --> rail-rail opamp
It typically has better that 1% linearity and should only have a few millivolt shift with temperature.

Thanks, Peter for that. I've checked output voltage.
I use voltage from Freequency converter and it's 10.4V. But at output maximum is only 8V. If it's problem with CMOS gate, it's good enough. I made settings on freequency converter to linerize input voltage to output freaquency.
But if it's a problem of ambient temperature, I will have big problems with changing weather and seasons.

That most likely means that the output circuit has been likely been damaged somehow and
will not be predictable until repaired