System and method for confirming radio frequency (RF) signal connections with multiple devices under test (DUTs) tested concurrently using replicas of a RF test signal. Cabled signal connections between the signal source and the DUTs are monitored by sensing levels of outgoing and related reflection RF signals. These signal levels are compared against similar signal levels when the outgoing RF signals are provided to reference impedances. Alternatively, the cabled signal connections have lengths of known signal wavelengths and the RF test signal frequency is swept such that minimum and maximum time delays between the outgoing and reflection RF signals go through minimum and maximum signal cycles with a difference of at least one full cycle. The reflection RF signal magnitude and phase are monitored, from which peak and valley signal level differences and phase changes are identified to determine return loss and phase changes indicative of DUT connection.