Large scale research experiments often require the use of highly specialized and sophisticated electronic equipment including computer-based data acquisition systems capable of gathering large amounts of data over very short time intervals. Equipment malfunctions can mean a loss of experimental data integrity and valuable research time. A diagnostic test system has been developed to monitor the electronic equipment of such an experiment, the Fast Neutron Hodoscope at the Transient Reactor Test Facility in Idaho. The system allows hodoscope electronics designers at Argonne National Laboratory in Illinois, and hodoscope maintenance engineers in Idaho, to observe simultaneously digital and analog signals from the hodoscope electronics while the hodoscope is in operation. The diagnostic test system can be controlled either locally by the engineers at the research site in Idaho or remotely by the designers in Illinois via a computer to computer telephone link between the two sites. As a result potential equipment problems as well as actual failures can often be pinpointed and corrected with minimal lost time and cost to the research program.