SSI encoder

LinuxCNC is reading the encoder 1000 times a second

When does the encoder value become correct?

i  uploaded2 videos. At the same position,i get 2 value when i turn on power of encoder. It is Z-Axis.

1.

2.

Sorry for being blunt, but why are switching power off to encoders with "machine enable"?
Encoders should be powered on and stay on as long as Mesa boards are on.
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I have used SSI (i think) serial absolute encoders, thanks to PCW, they are still in daily use for several years now, when the machine is first turned on the DRO shows some huge values, home all axis, and everything works perfectly.