TRUNK CALLING DISPLAY METHOD IN KEYPHONE SYSTEM

摘要

communication duration starting timer to inform that communication is started; initializing a buffer storing a cummunication duration and driving a communication duration in creasing timer; checking if it is in a state of a public telephone office line reserving and terminating in a state of accumulating the communication duration to buffer; producing a present communicating duration data and transmitting the data to the key-phone; and increasing a count value of the communicating duration storing buffer, driving the timer and advancing the third step.