The UR-9AH is classified as a CPU module for use with the Multilin GE series of universal relays, such as the F35 feeder protection system, the G60 generator management relay, or the N60 for network stability and synchrophasor measurement. A UR (universal relay) incorporated many of the pieces of equipment into one consolidated relay system for better efficiency and convenience for the end user. The UR-9AH is one model of CPU that can be found within the UR relays. Each UR relay will also contain a power supply, an inter-relay communications, a CT/VT input, a digital input/output, a transducer input/output, a communication switch and an IEC Process Bus. The order specifications function to select among the different hardware modules and software options. The UR-9AH is a CPU of the older models (9A, 9C, or 9D).  The unique description specified by the UR-9AH is the RS485 and RS485 (Modbus RTU, DNP). The newer CPU module that matches this characteristic is the 9E version. Since the UR-9AH is of the older models, then the CT/VT must also be an older version (8A, 8B, 8C, or 8D) within the UR F35 feeder protection system for example.