The present invention provides a field assembly for an electric motor and methods for assembling the field assembly. Upon reception of the interruption signal, the CPU backs up data, which is to be protected and stored in a RAM, by transferring it to a FLASH ROM through a bus. According to one aspect of the invention, the first and the second switching element each have an output which, depending on the first switching signal, produces an output signal at a first potential or at a second potential. After the parameter values are assigned to the transceivers, each of the transceivers is configured to transmit on the sub-channels determined at least in part by the parameter value assigned to the transceiver. The stop plate abuts against the lateral side of insulating base seat to resist against lateral external force and prevent the pivot member from being deformed.