| 摘要 |
PROBLEM TO BE SOLVED: To inform a data communication equipment for a wired line connecting to a mobile radio equipment that a level of a signal from a base station reaches a prescribed level or below. SOLUTION: A busy tone generator 12 has a 400Hz oscillator 12a. A state discrimination section 10 discriminates the communication enable state of a mobile radio equipment 7 based on the level of a signal on a control signal line CL and provides the output of the discrimination result to a control signal 11. The control section 11 applies on/off control to a relay 13 of a service tone generator 12 when the communication is disable based on the discrimination result to allow the generator 12 to generate a busy tone. The busy tone is fed to wired public line terminals L1, L2 of a facsimile equipment depending on a thrown position of a switch 2b. thus, the facsimile equipment 1 recognizes disable communication to avoid a useless call and the communication is interrupted by a regular procedure during the communication. |
