In harsh environments, we typically must install resolvers as feedback devices to survive the extremes of the application. Very few of the stepper drives/controls are configured to support resolvers, so Empire Magnetics has for many years provided an RDE product - Resolver to Digital Encoder - to support the resolver and output Encoder type A, B, Z signals. Some customers have issues with loss of power which equals loss of position, and for multi-turn applications, absolute position information is better than incremental.