Problem with two consecutive triggC commands

I have a situation where I'm trying to make a circular move with 5 points pTMeas1-ptMeas5. I want to trigger a signal at the beginning of the movement and reset it at the end of the movement.

I have TriggIOs defined for the signal, one for setting and one for resetting. I use them in various kinds of movements. This works perfectly in every other movement type I have, but these two TriggC commands give me trouble. Here is what I have at the moment:

! Define signal triggers.
TriggIO trSet,0.3\Start\DOp:=DO1,1;
TriggIO trReset,0.3\DOp:=DO1,0;
.....
! 5point circular movement
MoveL pTMeas1, vSlow, fine, tCurrent \WObj:=wSTN1;
TriggC pTMeas2, pTMeas3, vScan, trSet, z1, tCurrent \WObj:=wSTN1;
TriggC pTMeas4, pTMeas5, vScan, trReset, fine, tCurrent \WObj:=wSTN1;

I want to trigger the signal when the robot starts to move from pTMeas1 and reset the signal when it is reaching pTMeas5. However, the signal is reset already somewhere around ptMeas2 and pTMeas3. Any Idea what is wrong in this?

The points are approximately 1cm away from each other. The robot and one rotating unit are moving at the same time.

Thanks!