"Test PC is connected via Ethernet and UART to System Under Test."
I'm not quite sure where to put "the" in this situation. The reader is actual test engineer which should be familiar what is meant to be said in the sentence. English is not my mother language, thus I'm having difficulties with grammar and I can only correct my sentences based on a hunch. Which in this situation would be:
"The Test PC is connected via the Ethernet and the UART to the System Under Test."