Odd Reading of Encoder

[jxreyes181]

I have two motors setup the same way, but the reading of the encoders differ by a factor of 32 when they are in the same position.

 

I'm using a Absolute position Renisaw Biss C encoder. The resolution is 0.05 um, so I use a Ixx08=20.

 

For motor 1 I get the following readings: (This is correct)

The encoder sends 500000 in 26 bits. I process this data with the conversion table using Parallel Y word data, No filtering, and Normal Shifted, and so I get: (I8000=$278c00 I8001=$01800)

X:$3501 is 500000

X:$3502 is 0

I join this two in the recommended variable for actual position:

M162=(X:$3501 + X:$3502)*I108 (Not the actual code line)

=500000*20=10000000

And the Position Window in Pewin 32 reads 500000 cts.

 

This is correct. However, motor 3 is configured the same way, and makes all the calculations in the right way. But, the position Window in Pewin 32 reads 15625 cts. Is wrong by a factor of 32.

 

Im using a total of 4 motors, and only motor 3 makes this extra calculation.

 

Were does the Position Window of Pewin 32 takes the values from? Which variable.

 

Any ideas on what can be wrong?

 

 

THANKS

[Richard Naddaf]

Did you try swapping encoders with channels to see what happens?

Can you share your full setup parameters?

What hardware are you using (e.g. ACC-84E, Brick)?

Did you check to see if the position window in the PeWin is not scaled differently for channel 3?

What do #2P#3P report at those locations?

What do the serial encoder registers A and B read at those locations? You should use these to compute actual position.