The drop down list contains special entries that are either for binary mechs ( where more than one line is enabled simultaneously ), dual switch token mechs, or bit mask entries for below.
Newer techs tend have a dedicated 8 bit port for coin mechs and this is "mapped" into the switch array to make it more convenient to use and tend to need drop down bit values, though will usually work with single button numbers if the mech is a parallel one.
Older techs with S1/S10 mechs that use a single microswitch are normally connected to the switch array and can therefore be activated by a single button number.
Also when a value is selected from the drop down list, it will automatically time the pulse to prevent coin mech errors so it's preferable to use these where possible.
Excellent! I just added "All buttons" and found that button 1 is 10p, button 2 is 20p etc.
Thanks Wizard! 
Just saw your answer too Matty. Thanks for that.
I should be cooking on gas again now. Great stuff. Cheers :-)
Edited by uptown47, 20 June 2017 - 04:37 PM.
