| 摘要 |
PURPOSE:To automate the switching operation by allowing a control section of a modulator-demodulator to identify a specific character sent sequentially from a terminal equipment, to decide the coincidence between parity bit setting and a prescribed number and to send a character representing the start of the modulator-demodulator. CONSTITUTION:Modulator-demodulators 2-4 identify the setting of a character A representign the communication speed sent from a terminal device 1 and a character B representing a parity bit. When the devices 2-4 receive no B character after the character A is received twice, it is judged that the operation from the terminal device 1 is in error. Then an address character representing the number of the device 2 is sent from the terminal device 1 and a control secion 8 receiving the character allows a transmission section 6 to send the character sequence including the number of the device 2 to inform the start of the device 2 to the terminal device 1 when the number is identical to the set number by a switch 7. Thus, the switching operation is automated an the number of modulator-demodulators connected to the terminal device is increased.
|
