Interface units control communications between the ShapeArray™ and the data logger, as well as power. Unlike traditional geotechnical instruments that use only a few sensors, ShapeArrays often have hundreds of sensors in one instrument that require electricity. ShapeArray’s unique power requirements determine tight regulation to ensure optimum function. 

A 12V battery system can produce a range of fluctuating voltage—10.5V to 15V—depending on their condition. SAA232 contains a high-quality DC-to-DC converter that boosts and regulates the voltage supplied by 12V battery systems to a constant 13.5V. The SAA232 unit also extends the length of cable that can be run between the ShapeArray and its data logger, providing a 16.5V boost for longer cables. SAA232 also protects against electrical surges and voltage strikes.

There are two versions of the SAA232 interface: the SAA232, and the SAA232-5. The SAA232 is used to connect a single ShapeArray to a single COM port on a Data Logger, while the SAA232-5 can be used to connect up to 5 ShapeArray's to a single COM port.