JPH07177161A - Polling selecting method - Google Patents

Abstract

PURPOSE:To improve the transmission efficiency by storing the presence of a reply with respect to a polling sequence signal for each address of slave equipments and making different the frequency of polling between the addresses of an equipment giving a reply and an equipment not giving a reply. CONSTITUTION:In the method implementing transmission control among plural slave equipments 9-12 connected to a master equipment 8 via a transmission line based on address information of the slave equipments 9-12 stored in the master equipment 8, the master equipment 8 is provided with a polling control means and an operating state storage means. Then the operating state storage means detects whether or not the address is active based on the address information from the slave equipment and the presence of a reply from the slave equipment by using the polling control means and stores the detected state. The polling control means receives the storage content from the operating state storage means and controls the sequence of polling based on the stored content so that the frequency of polling is made different between addresses of the equipments 9, 10 giving a reply and the equipments 11, 12 not giving a reply.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polling selecting method in transmission control between a master device and a plurality of slave devices.

[0002]

2. Description of the Related Art Conventionally, in a configuration in which a master device and a plurality of slave devices are connected by a transmission line, for example, a polling sequential signal as shown in FIG. 3 is repeatedly sent from the master device. As a result, one slave device designated by the address number included in the polling sequential signal returns a response to the transmission path, and at the same time, exchanges data with the master device. The master device has a polling selecting method for controlling the transmission order of the address numbers in the polling sequential signal. One of the purposes is to improve the transmission efficiency by the polling selecting method.

A polling selecting method for improving the transmission efficiency is disclosed in, for example, Japanese Patent Laid-Open No.
As described in Japanese Patent No. 276176, a confirmation signal for requesting confirmation of the presence or absence of sequential transmission information in a slave device from a master device is sent to all slave devices as one signal, and a response signal from each slave device is sent. That receives and polls based on the response signal,
As disclosed in Japanese Patent Laid-Open No. 5-276168, the master device detects a call volume or the like generated in a unit time from a slave device, and polls control by allocating communication time based on the call volume or the like. Monoya, JP-A-3-131
No. 41, Japanese Patent Laid-Open No. 61-157132 discloses that the master device determines polling cycle information for each slave device and the reply contents of the slave device and controls the polling cycle based on them. As described above, there is a master device that detects and stores the utilization rate of a slave device and controls the polling frequency based on the detected utilization rate.

[0004]

In the above-mentioned prior art,
For example, a procedure for a confirmation signal and a response signal thereto is required, a call volume detection means is required, a means for determining polling cycle information and the response content of the slave device is required, and the utilization rate of the slave device is detected and stored. Means are needed.

Further, conventionally, in the master device, it is necessary to set, for each slave device, whether the slave device is operating or not, and the master device is changed every time the operating state of the slave device is changed. Had to reset.

An object of the present invention is to store the presence / absence of a response without requiring the above-mentioned procedure or means and without the need for resetting the master device, and to respond to the master device based on the stored contents. The polling control is performed to improve the efficiency of transmission between the slave device and the master device.

[0007]

In order to achieve the above object, the present invention provides a master device with means for storing the presence or absence of a response to a polling sequence signal for each address of a slave device. By controlling the polling order, the polling frequency is made different between the address of the slave device that responds and the address of the slave device that does not respond.

[0008]

As a result, by increasing the number of times of polling transmitted to the address of the slave device that is actually operating, the slave device that is not operating, is not connected, or is not powered is turned on. Since the number of times of polling transmitted to the corresponding address can be reduced, the efficiency of data transmission between the operating slave device and the master device can be improved.

Further, a polling sequence signal is transmitted to an address corresponding to a slave device that is not operating, is not connected, or is not powered on, even if the frequency is low, and Since it is possible to reconfirm whether there is a response to polling, even if the power of a slave device that has not been turned on is turned on, for example, even if the power of a slave device that is not turned on is changed, the master device must be reset for address management. You don't have to.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a diagram showing a system configuration example when the present invention is applied. This configuration will be briefly described. It is assumed that 8 is a master device, 9 and 10 are slave devices in operation, and M units are in operation including devices omitted between them. Slave devices 11 and 12 are in an inoperative state, and similarly, it is assumed that (N−M) units are in an inoperative state. Here, for convenience of description, the positions of the slave device group in the operating state and the slave device group in the non-operating state are shown separately, but the positions may be complicated.

The master device 8 has polling control means and operating state storage means. The operating state storage means operates the address based on the address information of the slave device from the polling control means and the presence or absence of a response from the slave device. Detects and stores the status or non-operation status. The polling control means receives the stored contents from the operating state storage means, and based on that, performs polling control using the polling selecting method described below.

An embodiment of the present invention will be described below with reference to FIG. In FIG. 1, M is the number of slave device addresses (operating state addresses) detected and stored in the operating state storage means of the master device, and N is the operating state address. It is the number obtained by adding the number and the number of addresses (addresses in the non-operational state) detected and stored in the non-operational state.

In FIG. 1, as shown at the top of the repetitive execution procedure, first, of the M operating addresses, the first address is polled (1). Next, polling is performed on the second address of the M addresses in operation (2). Thereafter, the same operation is sequentially repeated, and polling is performed on the Mth address of the M addresses in the operating state (3). In this way, the polling for sequentially operating the addresses in the operating state from the 1st to the Mth is expressed as an operating state polling procedure as shown by the broken line in FIG. 1 (4).

Next, in order to execute the polling for the address in the non-operational state, after performing the above-mentioned procedure (4) once, first, of the (NM) non-operational addresses, the first address is executed. Polling is performed for the address (5). Then, after the above-described procedure (4) is performed once again, polling is performed on the second address in the inactive state (6). Thereafter, the same operation is sequentially repeated, and polling is performed for the (N−M) th address in the inoperative state (7). By the above operation, the polling is performed at different frequencies for the address in the operating state and the address in the non-operating state, and this operation is repeated.

In the above-mentioned polling operation, if there is a response to the polling sequence signal transmitted to the address which was inactive in the previous polling, the master device transmits the predetermined transmission data. In accordance with the control procedure, information is transmitted and received to and from the slave device having the response address, and this address is regarded as a new operating state. For example, as the (M + 1) th operating state address, the above operation is performed thereafter. Polling is performed by incorporating it into the status polling procedure (4).

On the contrary, in the above-mentioned polling operation, when there is no response to the polling sequence signal transmitted to the address which was in operation in the previous polling, the master device determines that this address is not in operation. Assuming that the state has been reached, for example, as an address of the (N-M + 1) th non-operational state, it is removed from the polling procedure (4) of the above-mentioned operation state and incorporated into the polling procedure of the above-mentioned non-operational state with low polling frequency. Polling will be performed.

The polling may be repeated in order from the smallest address number to the largest, or conversely, from the largest address number to the smallest number. Of course, it does not matter if it is performed randomly.

Further, in the above description, it is assumed that every time the polling is sequentially performed once on all the addresses in the operating state, the polling is sequentially performed on one of the addresses in the non-operating state. Alternatively, as shown in FIG. 6, after performing the operation of sequentially polling the address in the operating state once or n times (n is an integer of 2 or more), one of the addresses in the inactive state or The operation of polling m (m is an integer of 2 or more) may be repeated. In addition, among the reference numerals of FIGS.
4, 15 and 16 are polls for addresses in the inactive state, and other reference numerals are the same as those in FIG. Further, FIG. 6 exemplifies a case of a combination of N, M, and m where (NM) is divisible by m.

FIG. 4 shows another system configuration example when the present invention is applied. 8'is a master device, 9'-1
0'is a slave device in an operating state. 11'-12 '
Is a slave device in a non-operational state.

A television monitor 20 is connected to the master device 8 ', and each slave device 9'to 12' connected to the master device 8'through a transmission line has a television camera, and the slave devices 9'to 12 'are photographed. The projected image is appropriately displayed on the screen 21 of the television monitor 20 connected to the master device 8 ′,
The system configures a system for monitoring the situation of the place where each slave device 9'-12 'is installed.

In this operation, when the master device 8'transmits a polling sequence signal on the transmission line, if the slave device of the address corresponding to the signal is in the operating state, the slave device will be on the transmission line and the television camera of the slave device. The video signal picked up in is transmitted. In this way, the master device 8 ′ sequentially receives the video signals from the slave devices in the operating state and generates the monitor signal, and the television monitor 2
It is sequentially switched to 0 and output. Further, when the slave device having the address corresponding to the polling sequence signal transmitted on the transmission line is in the inactive state, the video signal of the slave device is not transmitted on the transmission line.

In this case, by using the above-described polling / selecting method of the present invention, the polling repetition frequency for each of the slave devices 9'to 10 'in the operating state increases, so that the television monitor 2 of the master device 8'can be used.
0, each slave device 9'in operating state to be monitored
The period from which the images from 10 'to 10' are sequentially switched and displayed is shortened.

In the above embodiment, the system having the master device and the slave device has been described. However, in the distributed system, the present invention can be easily applied to a system in which the master device and the slave device are not always specified. It goes without saying that it can be applied to.

[0024]

According to the present invention, the procedure of the above-mentioned confirmation signal and the response signal thereto, the call quantity detecting means, the means for judging the polling period information and the reply contents of the slave device, and the utilization rate of the slave device. It is possible to perform polling control for improving the transmission efficiency by only storing the presence / absence of a response without requiring a means for storing the.

[Brief description of drawings]

FIG. 1 is a flowchart showing the operation of an embodiment of the present invention.

FIG. 2 is a diagram showing a system configuration example to which the present invention is applied.

FIG. 3 is a diagram showing an example of a polling sequence signal.

FIG. 4 is a diagram showing a second system configuration example to which the present invention is applied.

FIG. 5 is a flowchart showing the operation of the second embodiment of the present invention.

FIG. 6 is a flowchart showing the operation of the third embodiment of the present invention.

[Explanation of symbols]

4: Polling for one cycle of the address that is in the operating state, 5, 6, 7, 13, 14, 15, 16: Polling for the address that is in the inactive state, 8 8 ': Master device, 9, 10 , 9 ', 10': Slave device in operating state, 11, 12, 11 ', 12': Reve device in inoperative state.

Claims (4)

[Claims] 1. A polling selecting method for controlling transmission between a master device and a plurality of slave devices connected via a transmission line based on address information of the slave device held by the master device. , The address of the slave device that responded to the polling sequence signal including the above address information sent in accordance with a predetermined transmission control procedure is the address of the operating state, and the address of the slave device that did not respond is not working It is stored as an address of a status, and based on the stored content, the polling repetition frequency for the address in the operating state is set higher than the repetition frequency of polling for the address in the non-operating state. How to select polling. 2. The polling selecting method according to claim 1, wherein the master device sequentially polls an address, which is said to be in the operating state, among the plurality of slave devices and then is in the inoperative state. Is a polling selecting method that repeats the operation of polling one of the addresses that are A polling selecting method characterized in that one of the addresses is sequentially selected. 3. The polling selecting method according to claim 1, wherein the master device performs an operation of sequentially polling an address, which is in an active state, of the plurality of slave devices n times (n is (Integer of 2 or more) is a polling selecting method that repeats the operation of polling one of the addresses that are in the inactive state after repeating, The polling selecting method is characterized in that the execution is performed for addresses sequentially selected one from among the addresses determined to be in a non-operational state. 4. The polling selecting method according to claim 1, wherein the master device performs an operation of sequentially polling an address which is in an active state among the plurality of slave devices once or n times. A polling selecting method in which, after repeating (n is an integer of 2 or more), the operation of polling m addresses (m is an integer of 2 or more) out of the inactive state is repeated, The polling selecting method is characterized in that the polling procedure for the address in the non-operational state is executed for the addresses selected sequentially from the address in the non-operational state.