Stand-alone test device for testing command-response remote terminals

Abstract

A stand-alone test device for testing remote terminals intended for use on a command-response data bus which includes a single-purpose electrical waveform generator for generating a coded electrical waveform which is representative of a transmit command sequence which includes an address of a remote terminal under test, an electrical-to-optical converter (e.g., an LED driver and LED) responsive to the coded electrical waveform for producing a first coded optical waveform corresponding to the coded electrical waveform, and an optical transmission line (e.g., an optical fiber) having a first end coupled to the coded optical waveform and a second end coupled to an optical input of the remote terminal under test. The remote terminal under test is responsive to the coded optical waveform for producing an optical output indicative of the operational status of the remote terminal under test. The stand-alone test device further includes an optical-to-electrical converter (e.g., a photodetector and pre-amplifier) responsive to the optical output for producing an output electrical waveform, and an indication device (e.g., or oscilloscope or circuitry that recognizes the presence of data transitions and lights an LED) responsive to the output electrical waveform for producing an indication (e.g., a visual indication) of the operational status of the remote terminal under test.