Problem
Alpha Omega developed a number of inexpensive oceanographic instruments that were enclosed in urethane castings. The units were completely sealed to keep out water, so a non-intrusive method was needed to program the instruments and retrieve data.
Solution
We developed a proprietary inductive communications interface that utilized a coil inside the instrument casting and a separate coil in a wand that attached to the outside of the casting. The two coils served as windings in a transformer. Typically each instrument would have a transmit coil and a receive coil for full duplex communication, but some smaller units had a single coil for half duplex operation.
The assembly was housed in a durable metal package. Power was supplied by an external AC "wall wart." The external coil wand plugged into a jack on the front and another jack provided a RS-232 serial interface to a computer.
AO produced a program to run on computers to control the interface. It could send commands and programs to the instruments and recover data from the devices and store it on the computer.
Results
The Inductive Interface worked very effectively and was used with a variety of instruments. Each instrument used a custom pickup wand designed specifically for the package.