摘要 |
The present invention is primarily directed to rail car communication system and in particular communication system used to transfer data and voice communications from one car to another. The present invention has particular applicability for use in subway cars. A communication system using an E1 protocol is provided with an interface device which translates data received from a hardware device having, inter alia, a microprocessor and a universal asynchronous receiver transmitter (UART) used for serial communications such as COM 1-4. The asynchronous UART data is interfaced with the E1 channel. UART data transfers are usually done on a byte (8 bits) by byte basis but the present invention uses E1 timing and bit by bit communications. Additionally, data is normally sent at the data rate of the E1 channel not some other unrelated speed such as those used by a UART during serial communications. Also, the data is usually sent synchronously, like the E1 channel, not asynchronously, as with a UART.
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