Remote Indicating systems are systems that let pilots know where certain control surfaces are in their movements. Such systems include landing gears, flaps, and control valves.
There are two types of indicating systems used in airplanes. One is called an Autosyn system, Autosyn is a trademark name. It uses a single phase electromagnet for the rotor and a three phase delta wound connector stator for the coil. The other is called a Magnesyn system, it too is a trademarked name. The only difference between the two is that the Magnesyn uses a permanent magnet and the Autosyn uses an electromagnet.