초록 ▼

Apparatus in an automatic telecommunications system which communicates between a central location and at least one remote location over the switched telephone network, senses changes in loading of the telephone line which correspond to a telephone going off-hook, to serve as an indication that a tel

Apparatus in an automatic telecommunications system which communicates between a central location and at least one remote location over the switched telephone network, senses changes in loading of the telephone line which correspond to a telephone going off-hook, to serve as an indication that a telephone has gone off-hook and to cause the automatic telecommunications system to relinquish its use of the telephone line, or not to go off-hook if a telephone is in use.

대표청구항 ▼

A method of operating an automatic telecommunication system including a central location and at least one remote location and wherein a data reporting system including a modem is situated at the remote location for establishing data communications with the central location over the switched telephon

A method of operating an automatic telecommunication system including a central location and at least one remote location and wherein a data reporting system including a modem is situated at the remote location for establishing data communications with the central location over the switched telephone network, comprising the steps of determining prior to initiating communication with the central location whether a telephone at the remote location is off-hook and inhibiting communications with the central location is a telephone is off-hook, and further comprising the step of determining during the time that communications are established with the central location whether a telephone at the remote location goes off-hook includes generating a test signal and applying the test signal between ring and tip of a telephone line, providing the first and second integrator means having respectively short and relatively long integration time constants for integrating the test signal, comparing the integrated signal outputs of said first and second integrators, whereby a substantial difference between the integrated signal outputs of said first and second integrators is indicative that an additional load has been placed between tip and ring of the telephone line, corresponding to a telephone going off hook.