Time Dissemination by Telephone(TEL-JJY)
Timing of the time code transmission
The time transmission timing of this system is defined as below:
- 5.1 Data construction
5.1.1 Format - * Asynchronous serial signal
Data size 8 bit Parity None Stop bit 1 bit Xon/Xoff Yes - 5.1.2 Construction of transmitted data
- * Start bit + 8 bit data + Stop bit = 10 bit
About the contents of Input and output data, please reference the material of chapter 3.
- 5.2 Timing of data transmission
- 5.2.1 Synchronized point with the 1PPS signal
- * The end of the time code is expressed by the carriage return (CR) code, and the falling edge of the stop bit in the CR code is synchronized with the rising edge of the 1pps signal.
* The arrival time of the stop bit in the CR code is regarded as the time of this time code. The time code must be transmitted before the 1pps signal.
- 5.2.2 Reference point of the synchronization
- The input port of the transmission modem is defined as the reference point of the time synchronization with the 1PPS signal.
- 5.3 Loop back method of measuring delay time on-line
- Loop back circuit is realized by a hardware with the relay contact.
- 5.4 Delay
- Total delay measured by the system is the sum of the following:
- * Delay for the round trip
* Instrumental delay of the transmission modem
* Instrumental delay of the receiving modem - * Delay for the round trip