when the unit of parameter 'value' is taken from tango, the '$' units of other parameters are already replaced by the configured value and are not updated. this change fixes this. not yet tested on entangle, but a test with similar code works Change-Id: I87ad112b0965b39bb204d6c3d1fc1de6d4e14f60 Reviewed-on: https://forge.frm2.tum.de/review/c/sine2020/secop/playground/+/29357 Tested-by: Jenkins Automated Tests <pedersen+jenkins@frm2.tum.de> Reviewed-by: Enrico Faulhaber <enrico.faulhaber@frm2.tum.de> Reviewed-by: Markus Zolliker <markus.zolliker@psi.ch>