execucting blocks or functions consecutively

I need to execute blocks consecutively. I have a series of CAN messages that I have to send one after another. I've tried different iterations of triggered and enabled subsystems but no luck. The CAN message send blocks I'm using don't trigger any external events other than sending message. I need a way to be sure each function or block has executed fully before moving on to the next. I've tried assigning priorities but it doesn't seem to execute all priorities in that subsystem.