System of starting and terminating data communication

摘要

To provide a system of starting and terminating data communication, which can specify and access a slave (data terminal equipment) while maintaining the compatibility with the RS232C/UART interface. An address request signal is set to the high level, a slave is specified by adding data indicative of the number of the slave to serial transmission data, and the communication is started. The communication is terminated when no transmission data has been received for a predetermined time since the start of communication. <IMAGE>