That sounds like a job for some parallel loops, one reads the data from the serial connection, one that reads the TCP data, one which displays the data and one which hadles user events (pressing front pannel buttons). I would use queues to pass the data around from loop to loop. Data comes out from the TCP read and into the queue.
Now be careful if your data sources read at differetn rates and your display undates at yet another rate the data could become out of sync very quickly. What I have had happen is the one of my data sources reads much faster and builds up a large amout of data in the queue which is read more slowly.
good luck
