Sure, easy-peasy. Add a timer property to your DMM object and instantiate it in the constructor, with its mode sent to single (one-shot). Make a handler method for the timer’s Action event, in which you raise a Timeout event added to your DMM class. When you send a query (GET) message to the meter, restart the timer. You will have 3 DMM objects in your window and you can write commands to all of them. When the responses come in or timeouts occur, their corresponding events will fire, and in those events in your window you can add code to deal with those results.