TiTou,
Thank you for your help. I did not know about the event structure.
I will have 18 pairs of numbers to save.
The user switches between sum and difference voltages at various angles and reads from the Heidenhain.
I need to save a voltage and a reading from the Heidenhain for 9 angles and 2 voltages (sum and difference).
I would like to have the user press a button and save one voltage and a read from the Heidenhain.
Your event driven example could work.
Attached find my vi.
Regards,
tomieee