Storing ICE values to custom parameters

[cguer]

I'm getting some data from the kinematics of nullA, doing some calculations in ICE and then storing the data in a custom parameter to use as an expression on local kinematics for nullB. I think I'm having problems with the evaluation order of all this because the custom parameter is not updating.
The calculations I'm doing in ICE are fairly simple and could be done with expressions only but I was trying to see if I could do it in ICE. Is there a better way to set this up or is it just not recommended?

Thanks

[EricTRocks]

I don't think using ICE to set parameters then using those to set expressions would be stable. Why not just write to nullB's global kine? I know you're setting the local kine but you could get the same end result with some math.

maybe posting more info / ice trees / images could help.

[cguer]

I originally tried with setting the global kine directly but tried using custom Parameters because it was giving cycle breaking point errors.

I can do local/global conversions but I'm not that comfortable with matrix transformations yet. I'm able get nullA's local translation (with a neutral pose just for example purposes) and using it to multiply the global.kine of nullB directly without problem. All this is done in an ICE tree on an empty point cloud.
But if I also try set the global.kine for a child of nullB, I'm getting this error "# WARNING : 3000 - **** Cycle breaking point nullB_child.kine.global.ParentPoseCns_E". See screenshots for the setup I used.

I guess I'm mostly trying to figure out how to do the necessary calculations for a whole rig inside a single ICE tree (and if it's worth it vs. expressions).