Communication device and time synchronization system

摘要

In an embodiment, provided is a communication device connected to time servers via a network with transfer devices. In the communication device: a network controller receives a message containing time information counted by the time server and containing a network identifier, and obtains a receiving timing of the message; a network processing unit, when the network identifier in the message does not match with any network identifier, destroys the message; a protocol processing unit, when the network identifier has a match, calculates a time error by the time information in the message and the receiving timing, detects whether a first time server is malfunctioning, and when detected the first time server malfunctioning, outputs the time error calculated by a network identifier assigned to a second time server; a servo calculates an operation amount by the time error; and a clock varies a clock rate according to the operation amount.

主权项

1. A communication device that is connected to a plurality of time servers via a network configured with one or more transfer devices, the communication device comprising:
a network controller
configured to receive a message containing time information which indicates a timing counted by one of the time servers and containing a network identifier, andconfigured to obtain a receiving timing of receiving the message; a network processing unit configured to, when the network identifier specified in the message does not match with any network identifier assigned to any one of the plurality of time servers, destroy the message; a protocol processing unit
configured to, when the network identifier has a match, calculate a time error by referring to the time information specified in the message and by referring to the receiving timing,configured to detect whether a first time server is malfunctioning, andconfigured to, when it is detected that the first time server is malfunctioning, output the time error calculated by referring to a message containing a network identifier assigned to a second time server; a servo configured to calculate an operation amount by referring to the time error; and a clock configured to vary a clock rate according to the operation amount.