Compensation table - On/Off

I'm wondering how to see the effect of the compensation table on the motor.

I'm using I51 to switch between 0/1 and thought I find the effect in the difference between M161 and M162 or maybe in M169. However these don't seem to change.

The compensation table is defined as: #1 DEF COMP 2438,#1D,#1,16384 ...

Where can I find this?

Yes, I should have given more infos ;-)

So M169 is defined as "M169->D:$90" and gives back values according to the compensation table. I thought the table would roll-over outside of the given range, so I don't understand your comment with "in the range".

I can see the compensation table is recognized, but how can I see that it is switched of when I set I51=0? I want to compare the performance with and without compensation table and I don't see a big difference, so I wanted to make sure the switching is working.

You should see rollover. I referred to “in the range” to avoid any rollover effects.

Note the following:

If global variable I30 (new in V1.939 firmware) is set to the default value of 0 when the table is downloaded to Turbo PMAC, the correction value at 0 counts of the source motor is always 0. In this case, the last entry of the table must be set to 0, or there will be a discontinuity in the correction (and therefore a position jump) as the source motor passes either end of the table, rolling over the correction.

Most often, the correction is defined to be 0 at the zero position of the motor. If I30 is set to 1 when the table is downloaded to Turbo PMAC, the correction value at 0 counts of the source motor is set equal to the last entry of the table, guaranteeing smooth rollover of the table. If the last entry for the table is 0, the result will be the same regardless of the setting of I30.

I am certain that setting I51=0 will disable the table.

Here is an application note showing the calculations between Commanded (Mx61), Actual (Mx62) and Compensation Correction (Mx69) positions.

Leadscrew Compensation calculations.pdf