Modem device
First Claim
1. A modem device having a plurality of channels, each channel being connected to only one respective terminal which is external to said modem device, and each terminal being operative to issue to its respective channel a communication-start requesting signal, said modem device comprising:
- a modulator/demodulator for modulating/demodulating transmission/reception signals;
a selecting signal output means for monitoring communication-start requesting signals input from said plurality of channels, and outputting a channel selecting signal for selecting a channel through which one of the communication-start requesting signals has been input first; and
a switch means connected to all of said channels for establishing a connection between the terminal coupled to the channel selected by said selecting signal output means and said modulator/demodulator in response to the channel selecting signal supplied from said selecting signal output means, wherein said selecting signal output means, when one of the communication-start requesting signals from another channel is input while any of said plurality of channels is selected and in use, outputs a corresponding channel selecting signal for selecting said another channel after the use of the channel is terminated.
1 Assignment
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Accused Products
Abstract
A modem device enabling a single communication line to be shared by a plurality of terminal units, and needing no switching operation between the terminal units on transmission. In transmission, when a transmission-start request is supplied from a terminal unit of any channel, the state of the other channels are checked. If these other channels are all in idle state, a channel selecting signal for selecting the channel corresponding to the transmission-start request is turned on so as to couple the corresponding terminal unit to a modem section for starting the transmission. In reception, on the other hand, upon receiving a call, priority calling channel information having been set in a predetermined mode register is read out to turn on a channel selecting signal for selecting the channel indicated by that information. As a result, a terminal unit of the channel corresponding to the channel selecting signal is selected to enable the receiving operation.
13 Citations
6 Claims
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1. A modem device having a plurality of channels, each channel being connected to only one respective terminal which is external to said modem device, and each terminal being operative to issue to its respective channel a communication-start requesting signal, said modem device comprising:
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a modulator/demodulator for modulating/demodulating transmission/reception signals; a selecting signal output means for monitoring communication-start requesting signals input from said plurality of channels, and outputting a channel selecting signal for selecting a channel through which one of the communication-start requesting signals has been input first; and a switch means connected to all of said channels for establishing a connection between the terminal coupled to the channel selected by said selecting signal output means and said modulator/demodulator in response to the channel selecting signal supplied from said selecting signal output means, wherein said selecting signal output means, when one of the communication-start requesting signals from another channel is input while any of said plurality of channels is selected and in use, outputs a corresponding channel selecting signal for selecting said another channel after the use of the channel is terminated.
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2. A modem device having a plurality of channels, each channel being connected to only one respective terminal which is external to said modem device, and each terminal being operative to issue to its respective channel a communication-start requesting signal, said modem device comprising:
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a modulator/demodulator for modulating/demodulating transmission/reception signals; a selecting signal output means for monitoring communication-start requesting signals input from said plurality of channels, and outputting a channel selecting signal for selecting a channel through which one of the communication-start requesting signals has been input first; and a switch means connected to all of said channels for establishing a connection between the terminal coupled to the channel selected by said selecting signal output means and said modulator/demodulator in response to the channel selecting signal supplied from said selecting signal output means, wherein said selecting signal output means cancels the output of a corresponding channel selecting signal when said communication-start requesting signal is canceled.
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3. A modem device having a plurality of channels, each channel being connected to only one respective terminal which is external to said modem device, said modem device comprising:
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a modulator/demodulator for modulating/demodulating transmission/reception signals; a memory means for storing priority channel data for determining which of said plurality of channels should be a priority calling channel; a selecting signal output means for reading out the priority channel data stored in said memory means when a calling indication from a communication line is supplied, and outputting a channel selecting signal for selecting a corresponding channel; and a switch means connected to all of said channels for establishing a connection between the terminal coupled to the corresponding channel and said modulator/demodulator in response to the channel selecting signal supplied from said selecting signal output means. - View Dependent Claims (4, 5, 6)
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Specification