JPS6328148A - Polling device for multiple terminal - Google Patents

Abstract

PURPOSE:To shorten the waiting time of response for polling, and to rapidly process a request from a terminal side by a host side, by providing reception channels in multiple at the host side. CONSTITUTION:The polling is applied first on a first terminal equipment 21 in first group G1 from a signal processing unit 10, and before the response is received, the polling is applied on a fourth terminal equipment 24 in a second group G2. Similarly, the polling is applied sequentially in such a way that the polling is applied on a second terminal equipment 22 in the first group G1, after the polling have been applied on to the terminal equipment in a fourth group. On the other hand, while the signal processing unit 10 applies the polling on the terminal equipment in a different group, terminal equipments 21-2N return the response through the use of a first-a fourth frequency bands fr1-fr4. In this way, it is possible to eliminate the waiting time of the response.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a polling type communication device that specifies a specific terminal among a large number of terminals and instructs that terminal to start transmission. Regarding bidirectional CA, the performance is determined by the response speed, especially when a large number of terminals are connected.
The present invention relates to a polling device suitable for TV systems and the like.

[Conventional technology]

Conventionally, in a communication device that employs frequency division multiplexing, the signal processing unit 41 on the host side has one transmission channel cht and one reception channel chr, as shown in FIG. For example, the unit 41 performs polling pi on the wIJl terminal Tx[, waits for a response r1 from the terminal Tr, and then polls the next second terminal T21C polling p2 via the modem 42. I was supposed to do it.

[Problem that the invention seeks to solve]

In the conventional communication method described above, since the host side had only one sending channel and one receiving channel, it was necessary to wait for a response from the terminal side every time the host side was used for boring, and it was difficult to connect a large number of terminals. In this case, the disadvantage is that the polling cycle takes a long time.

The polling device of the present invention reduces the waiting time on the host side for polling by providing multiple receiving channels on the host side in order to shorten the polling cycle, which was problematic when a large number of terminals are connected. There are many things to do.

[Means for solving problems]

The polling device of the present invention is a communication device that connects a large number of terminal devices with cables and polls these terminal devices, in which the terminal devices are divided into groups and the polling is performed sequentially for each different terminal device in different groups. and means disposed in each of the terminals to respond to the polling in a different frequency band for each group;
It is characterized by having the following.

Therefore, by adjusting the receiving channels on the host side to match the number of different frequency bands, the polling cycle can be shortened and the host side can quickly process requests from terminals.

([Example] The present invention will be described below with reference to the drawings with reference to its embodiments.

FIG. 1 is a block diagram schematically showing an embodiment according to the present invention. The signal processing unit 10 on the host side receives and processes instructions from each of the terminals 21 to 2N, performs signal processing, and notifies the terminals 21 to 2N of the results.

The terminal devices 2l-2N accept requests from each user,
The contents are notified to the signal processing unit 10 via the coaxial cable 18.

The modem 11 demodulates the frequency division multiplexed reception signal from the coaxial cable 13, converts it into a digital signal for each of the first to fourth reception channels (chr 1 to chr 4), which will be described later, and sends the signal to a signal processing unit (10). The receiver can be removed, and the signal processing unit coaxial cape/I/13
It is sent to

In other words, in this embodiment, as shown in FIG. Reception channel Chr l~Chr
There are nine frequency bands for reception corresponding to frequency frl = fr4.

In this case, the terminal side collects several terminal devices into one group and decides in advance to use one transmission frequency band.For example, in the case of Fig. 1, wfJ1 group Gl is 1 to aE8 terminals 21 to 28,
It is predetermined in advance that the frequency band frl will be used, and the second group G2 will use the frequency band frf as the fourth and fifth terminals 94.25.

FIG. 2 is a block diagram showing the main parts of FIG.
is composed of a hybrid branching device Ha connected to the coaxial cable 18, a modulator Mo and four demodulators Do 1 to Do 4 connected to the branching device Ho,
These modulators MO and demodulators Dol-DO4 are connected to a signal processing unit 10 via a transmission channel cht and first to fourth reception channels chrl to chr4, respectively.

The terminal device z1 includes a hybrid branching device H1 connected to the coaxial cable 18, a modulator Mx and a demodulator D1 connected to the branching device H1, and a terminal connected to the modulator Ml fk and the demodulator Dl. It is composed of a device T21.

In the present embodiment having the above-described configuration, a first ring is first applied from 10 in the signal processing unit to the first group Gl. Similarly, polling is applied to the fourth (not shown), and so on.

On the other hand, on the terminal devices 21 to 2N side, while the signal processing unit 10 is polling terminal devices in different groups,
A response is returned using the first to fourth frequency bands frl=fr4.

Therefore, it is possible to eliminate the response delay time which was a problem in the conventional example shown in FIG.

〔Effect of the invention〕

As described above, the host side has multiple reception channels, so the waiting time for a response to polling can be shortened, so that the host side can quickly process requests from the terminal side.

[Brief explanation of the drawing]

FIG. 1 is a block diagram schematically showing an embodiment of the present invention, FIG. 2 is a schematic block diagram of the main parts of the same, FIG. 8 is an explanatory diagram of the embodiment, and FIG. 4 is a diagram of the conventional example. It is a schematic block diagram. 10... Signal processing unit. 11...Modem. ]8...Coaxial cable. 21~2N...Terminal. Ho, Hl...Hybrid branching device. Mo, Mr...Modulator. Dol~DO4, DI... Demodulator.

Claims (1)

[Claims] In a communication device that connects a large number of terminals with cables and polls these terminals, the terminals are divided into groups, and the polling is performed sequentially for each different terminal in different groups. 1. A polling device for a large number of terminals, comprising: means for applying the polling; and means disposed in each of the terminals to respond to the polling in a different frequency band for each group.