Designing a test system using a remote test server

I'm trying to design a test system to test an embedded realtime software. Is it possible to use TTCN-3 to control hardware components like UART or Digital I/O Card to stimulate SUT? If not could you offer a framework or methodology?

 _________________________
|   Test Operator Client  |  <- Test Script  [Operator]
 -------------------------   
   | Test Behavior    ^
   v                  | Test Result 
 ________________________
|  Test Execution Server |
 ------------------------   
    | Stimulation (Send UART Message, Set Digital Output etc...) 
    |              ^
    |              | Observe SUT Response ( timestamp, digital/analog IO etc...)
    v              |  
 ___________________________________
|   System Under Test (Real Time)   | 
 -----------------------------------