Thanks. The frontend gateway does house the visuals with the backend housing the plc connections. The frontend is using remote tag providers to access the tags which live on the backend. I am doing my work on a VM and I am accessing the two gateways remotely through my VM. I start the vision client using the Tools-->Launch Project link through the project explorer.
A lot of moving parts so it is a little confusing.
End of the day I have it working correctly when I run the gateway script on the backend, getting the current date and time from the computer running the backend. On the button press I have the frontend gateway sending a message to the backend gateway project. The backend then sets the date and time using system.date.now() which is also coming from the backend gateway computer.
I get why people do a frontend backend setup but it does add some complications at times. Single gateway makes life much easier.