Thank you for the input. As you point out, I think I’m doing (roughly) the right things – at least I believe what I’m doing is ‘logical’ :-)
I will do a little more research based on your input. BTW, I did name ports differently to interfaces. I have now discovered why I didn’t get it to work – I hadn’t changed the BP Preferences for OAL back to the default of not using the interface name for component communication. The references to the keyword ‘send’ lead me astray too!
Actually, it’s a backward compatibility issue that is driving the use of interface naming. At least for now!