Simple Monitor for SDI-12 signals

Simple Monitor for SDI-12 signals

SDI-12 is a digital interface used to communicate between a logger and smart sensors.
When SDI-12 connection is not working, it can be frustrating to diagnose the problem.
This Tech Note describes how to set up a simple monitor circuit to monitor the data on an SDI-12 bus using a PC with USB port. The design uses readily available components for a quick and easy diagnostic tool.