Polling communication system and polling control method

• US 20030137986A1
• Filed: 07/18/2002
• Published: 07/24/2003
• Est. Priority Date: 01/18/2002
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Hirao, Kyoko, Kaku, Takashi
• Granted Patent: US 7,286,494 B2
• Time in Patent Office: Days
• US Class Current: 370/449
• CPC Class Codes: H04B 2203/5408 using protocols
• CPC Class Codes: H04B 2203/5425 improving S/N by matching impedance, noise reduction, gain control
• CPC Class Codes: H04B 2203/5445 Local network
• CPC Class Codes: H04B 3/542 the information being in digital form
• CPC Class Codes: H04L 12/403 with centralised control, e.g. polling

Abstract

A polling communication system includes a main station and a plurality of sub stations connected to the main station. The main station includes an address control part and a polling control part. The address control part divides a predetermined polling cycle into a plurality of kinds of polling intervals each having a different number of times of polling, and holds addresses of polling target sub stations corresponding to the respective polling intervals. The polling control part switches the polling intervals and changes the addresses in the address control part according to states of the sub stations. Each of the sub stations includes another polling control part that sends a response when the sub station is polled by the main station.

Claims

1. A polling communication system, comprising:

a main station; and

a plurality of sub stations coupled to the main station,

said main station including;

an address control part that divides a predetermined polling cycle into a plurality of kinds of polling intervals each having a different number of times of polling and holds addresses of polling target sub stations corresponding to the plurality of kinds of polling intervals; and

a first polling control part that switches the plurality of kinds of polling intervals, and at the same time, controls movement from one polling interval to another polling interval of the addresses of the sub stations held in the address control part according to states of the sub stations including whether or not there are responses from the sub stations,

each of the sub stations including;

a second polling control part that sends a response depending on existence of transmission data when the sub station is polled by the main station.

2. The polling communication system as claimed in claim 1, wherein:

the address control part switches between a low-speed polling interval and a high-speed polling interval in the predetermined polling cycle and includes a low-speed polling address table representing addresses of low-speed polling target sub stations on which the polling is performed in the low-speed polling interval and a high-speed polling address table representing addresses of high-speed polling targets sub stations on which the polling is performed in the high-speed polling interval, and

the first polling control part switches between the low-speed polling interval and the high-speed polling interval, performs the polling according to the addresses in the low-speed polling address table in the low-speed polling interval, performs the polling according to the addresses in the high-speed polling address table in the high-speed polling-interval, changes the sub stations that respond to the polling in the low-speed polling interval to the high-speed polling target sub stations and changes the sub stations that do not respond to the polling in the high-speed polling interval to the low-speed polling target sub stations, and the sub station includes a polling control part that sends a response depending on the existence of transmission data in response to the polling by the main station.

3. The polling communication system as claimed in claim 2, wherein the first polling, control part switches between the low-speed polling interval and the high-speed polling interval according to number of the low-speed polling target sub stations and number of the high-speed polling target sub stations.

4. A polling communication system, comprising:

a main station;

a plurality of sub stations; and

a home electric appliance network,

wherein the main station includes a first polling control part that divides a predetermined cycle into a communication interval of the home electric appliance network and a polling communication interval of the main station and the plurality of the sub stations, and performs polling on the plurality of the sub stations in the polling communication interval, and

each of the sub stations includes a second polling control part that sends a response depending on existence of transmission data in response to the polling by the main station.

5. The polling communication system as claimed in claim 4, wherein:

the first polling control part divides a predetermined cycle into the communication interval of the home electric appliance network and the polling communication interval of the main station and the plurality of the sub stations, further divides the polling communication interval into a plurality of kinds of polling intervals each having a different number of times of polling, and performs the polling by switching the plurality of kinds of polling intervals, and

the main further includes;

an address control part that holds addresses of polling target sub stations in the plurality of kinds of polling intervals.

6. A polling control method for a polling communication system having a plurality of sub stations coupled to a main station, comprising the steps of:

dividing a predetermined polling cycle of the main station to the plurality of sub stations into a plurality of kinds of polling intervals each having a different number of times of polling;

changing the sub stations that have not responded to the polling to polling target sub stations in a polling interval having a few times of polling; and

changing the sub stations that have responded to the polling to polling target sub stations in a polling interval having many times of polling.

7. The polling control method as claimed in claim 6, further comprising the steps of:

dividing the predetermined polling cycle of the main station to the plurality of sub stations into a low-speed polling interval and a high-speed polling term;

changing the sub stations that have responded to the polling in the low-speed polling interval to high-speed polling target sub stations; and

changing the sub stations that have not responded to the polling in the high-speed polling interval to low-speed polling target sub stations.

8. The polling control method as claimed in claim 7, further comprising the step of:

changing the low-speed polling interval and high-speed polling interval in the polling cycle according to the number of the low-speed polling target sub stations and the number of the high-speed polling target sub stations.

9. A polling control method to be implemented in a main station in a polling communication system including the main station, a plurality of sub stations and a home electric appliance network, comprising the steps of:

dividing a predetermined cycle into a communication interval of the home electric appliance network and a polling communication interval of the main station and the plurality of sub stations; and

polling the plurality of sub stations in the polling communication interval.

10. The polling control method as claimed in claim 9, further comprising the steps of:

dividing the polling communication interval into a plurality of kinds of polling intervals each having a different number of times of polling;

changing the sub stations that have not responded to the polling by the main station to polling target sub stations in a polling interval having a few times of polling; and

changing the sub stations that have responded to the polling to polling target sub stations in a polling interval having many times of polling.

11. A main station which couples to a plurality of sub stations, comprising:

an address control part that divides a predetermined polling cycle into a plurality of kinds of polling intervals each having a different number of times of polling and holds addresses of polling target sub stations corresponding to the plurality of kinds of polling intervals; and

a polling control part that switches the plurality of kinds of polling intervals, and at the same time, controls movement from one polling interval to another polling interval of the addresses of the sub stations held in the address control part according to states of the sub stations including whether or not a response is received from the sub stations, said response being received depending on existence of transmission data when the sub station is polled.