JP2957361B2 - Polling method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polling method,
In particular, the present invention relates to a polling system for transmitting a data signal from a plurality of terminal devices connected in a multi-drop format (branch system) to a master station as in a CATV system or the like.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 3, a polling system employs a master station 20 and a plurality of terminal devices 21-i (i = 1, 2).
, N) are connected in a multi-drop format, and data transfer from the terminal device 21-i to the master station 20 is performed as follows.
As shown in FIG. 4, after receiving the polling signal 5 shown in FIG. 5 from the master station 20, the terminal device 21-i sends out the data signal 16 for the polling.

In FIG. 3, a plurality of data transmission / reception terminal devices 21-i are branch-connected to a data transmission line 22 having one end connected to a master station 20.

In this multi-drop type communication system, when data is transferred from each terminal device 21-i to the master station 20, the master station 20 transmits the data to the terminal device 21-i at the timing shown by the arrow in FIG. Polling is sequentially performed for each terminal, a polling signal 5 is transmitted, and a data signal 16 responding to the polling from each terminal device 21-i is received.

That is, an address for specifying each terminal device 21-i is assigned in advance, and as shown in FIG. 4, the master station 20 first transmits the polling signal 5 shown in FIG. Transmit to the device 21-1.

In FIG. 5, F1 is a flag signal , CTL
2 is a control division signal, SPID3 is a call termination terminal ID for designating a terminal device for stopping the call, and BCC4 is an error detection code.

The terminal device 21-
1 sends the data signal 16 shown in FIG. In FIG. 6 , F11 is a flag signal, CTL12 is an information division signal, ID13 is a transmitting terminal ID for designating a transmitting terminal, INFO14 is information, and BCC15 is an error detection code.

The master station 20 receives the data signal 16 sent from the terminal device 21-1, and then receives the next terminal device 2
The terminal device 21-2 sends out the polling signal addressed to 1-2, and returns the data signal 16 for this polling to the master station 20.

In the same manner, the master station 20 is connected to the terminal 2
, 21-n, and sequentially executes polling, and receives data signals from the terminal devices 21-3,..., 21-n.

[0010]

In the conventional polling method described above, the master station 20 sequentially sends polls to the terminal devices 21-i, and performs polling even for terminal devices having no data. As a result, there is a disadvantage that the polling time becomes longer.

[0011] In addition, when the power of the terminal device is cut off, retransmission is performed, so that the polling time becomes longer.

SUMMARY OF THE INVENTION It is an object of the present invention to eliminate the above-mentioned drawbacks. By eliminating polling to a terminal device having no data to be transmitted, polling efficiency can be significantly improved. It is to provide a method.

[0013]

A polling method according to the present invention.
In a polling method in which a plurality of terminal devices are connected to a master station via a data line in a branching manner, and the master station collects data by polling, the plurality of terminal devices are connected to each other.
And a hybrid circuit that branches and inputs the signal from the master station.
And receiving the branch input by the hybrid circuit
A data receiver that separates and outputs a polling signal and a data signal
A receiving section, a receiving section for receiving data signals, and a
Polling judgment processing unit that performs judgment processing of the ringing signal
And a call stop that performs call stop judgment processing for the own terminal
Call determination processing unit, and a call processing unit that performs a call stop release determination processing
Performs random time counting with the call stop clear judgment processing unit.
A first timer and a second timer for measuring a certain time.
A data transmission unit for transmitting a data signal;
And a transmission processing unit for creating a data.
In addition, the polling determination processing unit is configured to perform polling from the master station.
A call request is generated in the own terminal device when a ring signal is received
If so, notify the data transmission unit,
The first to wait for a random time for data transmission
The call stop determination processing unit starts the timer of
When a polling signal to stop calling is received from the station
When a call request is issued at the terminal device
The second timer is started to wait for a certain time for communication.
The call stop clear judgment processing unit operates from the master station.
Own terminal when receiving clear signal to release call suspension
Initialize the device, and the data transmission unit
Upon receiving the notification from the
When a call request is being generated in the own terminal device,
The first timer and the second timer are both timers.
Only when it is in the timeout state,
And transmitting the data signal.

[0014]

Next, the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of one embodiment of the present invention. FIG. 1 shows a configuration of a terminal device according to the present invention. A hybrid circuit 31 for branching and inputting a signal from a master station, and a data reception for receiving a branching input by the hybrid circuit 31 and separating and outputting a polling signal and a data signal. Unit 32, a reception processing unit 33 for receiving a data signal, a polling determination processing unit 36 for performing a polling signal determination process, a call termination determination processing unit 37 for performing a call termination determination process for the own terminal, A call stop clear determination processing unit 40 that performs a call stop release determination process;
A configuration including a timer (1) 38 for counting a random time, a timer (2) 39 for counting a fixed time, a data transmission unit 34 for transmitting a data signal, and a transmission processing unit 35 for generating transmission data. Having.

Next, the operation of this embodiment will be described.

The data signal sent from the master station 20 is branched and input by the hybrid circuit 31,
Is output to

The data receiving section 32 separates the data signal into a polling signal from the master station 20 and a normal data signal, and sends the data signal to a reception processing section 33, which performs reception processing.

On the other hand, the polling signal is a polling judgment process.
Processing unit 36 , call stop determination processing unit 37, and call stop
A is supplied to the determination processing unit 40 .

When the polling signal is received, the polling determination processing unit 36 notifies the data transmission unit 34 and waits for a random time for data transmission.
The timer (1) 38 is started.

When receiving the SPID3 of FIG. 5 for designating the stop of the call, the timer (2) 39 is started in order to wait for the call for a predetermined time.

When the timer (1) 38 and the timer (2) 39 have timed out, the data transmitting unit 34 is notified that the call is released.

The data of the transmission processing unit 35 is sent to the data transmission unit 34, and is transmitted to the master station in a callable time zone at the timing of polling reception from the master station.

FIG. 2 is a diagram showing an example of the operation sequence of the embodiment of FIG. Hereinafter, the operation of this embodiment will be described in more detail with reference to FIG.

Referring to FIG. 2, the polling from the master station 20 is performed first on all terminal devices 21-i (i = 1, 2, 3,...,
n).

Each of the terminal devices 21-i, when a call request is generated by the terminal device, transmits the I-address of the terminal device shown in FIG.
A timer (1) 3 as a random timer for transmitting a data signal 16 with D and information to the master station 20 and at the same time determining whether or not to respond to the next polling
8 is operated.

Although data signals 16 from a plurality of terminal devices 21-i arrive at the master station 20, the master station 20 performs polling again because a collision occurs and it cannot be recognized correctly.

At this time, each terminal device transmits the data signal 16 to the master station 20 only when the terminal device has a data signal to be transmitted and the timer (1) 38 has timed out. I do.

When the master station 20 recognizes a collision again, the same polling as described above is repeated, and each terminal device 21-i is similarly repeated.

When the master station 20 receives a data signal from only one terminal device, it determines that no collision has occurred, and when transmitting the next polling signal, the master station 20 stops calling the terminal device. The polling signal 5 to which the device ID 3 is added is transmitted.

The terminal device corresponding to the call stopping terminal device ID3 does not make any call for a certain period of time, and the terminal device which does not correspond to the stop of the calling repeats the same operation as before.

When the master station 20 is initially started, for example,
To initialize the terminal device 21-i, the master station 2
0 indicates the C of the polling signal 5 to the terminal device 21-i.
A clear signal for calling stop release is transmitted by giving meaning to TL2 and SPID3.

In FIG. 2, t1-1 and t2-
1, t3-1, etc., each have the data to be transmitted and indicate a state in which the timer (1) 38 can make a call due to timeout, and t2-2 indicates that the data signal of the terminal device 21-2 is not transmitted. The timer (2) 39, which has been received by the master station 20 and has been designated by the master station to be unable to call, indicates a certain period of time.

In this way, it is possible to avoid a collision of a response call to the polling of the master station 20 and to secure a polling in which unnecessary repetition of data response transmission is largely suppressed.

In the above-described embodiment, each terminal device is not divided into a plurality of groups. However, whether to divide each terminal device into a plurality of groups depends on the collision time caused by the simultaneous call generation. It can be arbitrarily determined as desired by taking into consideration.

[0036]

As described above, according to the present invention, a plurality of terminal devices operated in a polling system make a call to the master station after a random time from the polling of the master station, and the accepted terminal devices are: By not calling again until a clear signal is received from the master station or a timeout occurs in the terminal device for a certain period of time, call collision on the transmission line is avoided and polling efficiency can be significantly improved. This has the effect.

Further, the master station does not need to resend the polling to the power-off terminal device, so that the polling efficiency can be further improved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.

FIG. 2 is a diagram showing an example of an operation sequence of the embodiment of FIG.

FIG. 3 is a block diagram showing a basic configuration of a polling method.

FIG. 4 is a diagram showing an operation sequence of FIG. 3;

FIG. 5 is a data format of a polling signal in the embodiment of FIG. 1;

FIG. 6 is a data format of a data signal in the embodiment of FIG. 1;

[Explanation of symbols]

 Reference Signs List 5 polling signal 6 data signal 31 hybrid circuit 32 data reception unit 33 reception processing unit 34 data transmission unit 35 transmission processing unit 36 polling judgment processing unit 37 call stop judgment processing unit 38 timer (1) 39 timer (2) 40 call Stop clear judgment processing unit

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-254541 (JP, A) JP-A-63-299597 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H04L 12/40

Claims (2)

(57) [Claims] 1. A polling method in which a plurality of terminal devices are connected to a master station via a data line in a branching manner, and the master station collects data by polling.
Are the hives that branch and input the signal from the master station.
The branch input by the lid circuit and the hybrid circuit
Receives and separates and outputs to polling signal and data signal
Data reception unit and reception processing for receiving data signals
Section and a polling judgment section for judging a polling signal.
The call processing unit performs a call termination determination process for the local terminal.
The call termination determination processing unit and the call termination release
Call stop clear judgment processing unit to perform
A first timer that measures time and a second timer that measures time
A timer, a data transmission unit for transmitting a data signal,
And a transmission processing unit for generating transmission data.
Polling method. 2. The system according to claim 1, wherein the polling determination processing unit is configured to:
When a polling signal is received from an
When the request is generated, the data transmission unit is notified.
In order to wait for a random time for data transmission
Activating the first timer, and determining whether the call has been stopped.
Sends a polling signal from the master station to
When a call request is issued in the local terminal device
Is the second to wait for a certain time for data transmission.
The timer is started and the call stop clear judgment processing unit
Received clear signal to release call suspension from the parent station
When the terminal device is initialized, the data transmission unit
Receives the notification from the polling determination processing unit
When a call request is generated in the own terminal device.
And the first timer and the second timer
Only if both of them have timed out
Transmitting a data signal to the master station
The polling method according to claim 1.