Thanks SSC that seems to work. I have a few questions if that's OK.
1) Should what I did have worked and this is a get round or was there somtehing fundementaly wrong in my aproach?
2) Is !MSCounterFreeRunning a reserved hot paramitor that I don't know about ? Couldn't find it in Kyma X revealed.
3) Not sure I understand what TransformEventValues is doing and why it is needed in this case. Is it to allow a value to be read by formula whose output is activly needed to determine the value (gaurenteeing the one tick delay)? I did notice that sometimes a STGC was capable of writing it's value to a hot parameter instantaniously (without a 1 tick delay) and sometimes not. Is this a technuque of gaurenteeing circular dependacies are legitimaised with a one tick delay?
Thanks for your help