JPH1065716A - Data transmitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance resposiveness in a device to be controlled, which is connected to slave stations by shortening the data refresh time of control data to the slave stations with simple configuration. SOLUTION: When control data is transmitted to the slave stations 2n, a master station 1 transmits continuous correlative address data at every slave station 2n by selecting based on an absolute address which is previously set in the slave stations 2n first so as to assign different correlative addresses at every slave station 2n and, then, transmits control data altogether to the slave stations 2n corresponding to the applying correlative address by a timing based on the correlative address. Then, the slave stations 2n fetch control data from the master station 1 by the timing based on the assigned correlative address. Thus, the master station 1 shortens the data refresh time of control data as to the slave stations 2n.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data transmission apparatus in which a master station and a plurality of slave stations are connected through a transmission line, and a controlled device connected to each slave station is controlled by the master station.

[0002]

In recent years, remote control of a controlled device connected to a slave station by operating a master station to transmit data to a predetermined slave station from a plurality of slave stations. Is provided. In other words, the master station sequentially outputs the listener address data and control data for individually designating each slave station from the plurality of connected slave stations to the signal transmission path, and the slave station outputs the address data input from the signal transmission path. When it is determined that the designated station is designated, the controlled device is controlled based on control data following the address data.

In recent data transmission devices,
After transmitting address data specifying each slave station individually from the master station, receiving response data from each slave station and confirming that each slave station is operating normally, then transmitting control data In some cases, a controlled device connected to each slave station is remotely controlled.

In general, when controlling each of the slave stations, the master station also monitors them at the same time. In contrast to the talker address data for individually designating the slave stations, the slave station transmits the monitoring data to the master station. It is sent back to the side to inform them of individual abnormalities.

As a data transmission method of the above-described transmission device, a polling method is used to determine a response time, and the first slave station, the second slave station,... When the transmission is completed, it returns to the beginning and starts from the first slave station.

However, if normal transmission is performed by the polling method, the time required for one scan to communicate with all the slave stations increases as the number of slave stations increases. In addition, the interval time of data refresh (data update) of the controlled device also becomes long. For this reason, control data from the master station cannot be given to a controlled device that requests data at high speed for a high-speed response, and there is a possibility that the controlled device cannot be used at high speed.

In this case, it is conceivable to reduce the number of connected slave stations and configure a plurality of similar control systems for high-speed response of the controlled device. However, the cost increases and the control becomes complicated. Become.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to shorten the data refresh time of control data to a slave station with a simple configuration to thereby reduce the response of a controlled device connected to the slave station. It is an object of the present invention to provide a data transmission device capable of improving performance.

[0009]

SUMMARY OF THE INVENTION The present invention relates to a data transmission apparatus in which a master station and a plurality of slave stations are connected through a transmission line, and a controlled device connected to each slave station is controlled by the master station.
The master station first assigns a different relative address to each slave station by transmitting continuous relative address data to each slave station by selecting based on an absolute address set in advance to each slave station, Control data addressed to the slave station corresponding to the relative address is transmitted at a timing based on the relative address, and the slave station captures the control data from the master station at a timing based on the assigned relative address (claim) Item 1).

According to such a configuration, when transmitting the control data to the slave station, the master station first transmits successive relative address data to each slave station by selecting based on the absolute address. Thus, different relative addresses are assigned to each slave station. Subsequently, the master station transmits control data addressed to the slave station corresponding to the relative address at a timing based on the relative address. Then, the slave station takes in control data from the master station at a timing based on the assigned relative address. Therefore, since the control data can be transmitted to the slave station without transmitting the absolute address from the master station, the transmission time of the control data can be reduced.

In the above configuration, when transmitting the control data addressed to each slave station, the master station transmits a reset signal for instructing a start of control data transmission by broadcast simultaneously received by the slave stations through the transmission path. May be transmitted (claim 2).

[0012] According to such a configuration, the master station can notify the slave station of the start timing of the control data by transmitting the reset signal by broadcast communication. It is possible to reliably recognize the data transmission timing.

The master station may collectively transmit control data addressed to each slave station in the order of the corresponding relative addresses. According to such a configuration,
The transmission time of the entire control data can be greatly reduced.

When the slave station recognizes its own relative address by selecting by the master station,
From the next time, control data addressed to itself may be fetched at a timing based on the relative address (claim 4).
According to such a configuration, the slave station, once recognizing its own relative address, fetches the control data based on the relative address from the next time, so that the transmission time of the control data from the next time can be reduced. it can.

When the control data is transmitted from the master station at a time, the slave station counts the number of control data to be transmitted, and takes in the control data addressed to itself at a timing based on the count value. (Claim 5). According to such a configuration, the slave station can reliably take in the control data addressed to itself without storing all of the control data from the master station.

[0016]

FIG. 1 shows a first embodiment of the present invention.
This will be described with reference to FIGS. FIG. 2 shows the overall schematic configuration. In FIG. 2, a master station 1 and a first slave station 2
., The second slave station 202, the third slave station 203,... Are connected via the signal transmission line 5. The master station 1 can sequentially output address data and predetermined data that individually designate the slave stations 201, 202, 203,... To the signal transmission path 3. In addition, each slave station 201,
When the address data input from the signal transmission line 3 is an address designating the own station, 202, 203... Take in predetermined data to be transmitted next into the own station.

Here, in the system of the present embodiment,
Data exchange according to the polling selecting method is only initial polling performed by the master station 1 for the first time and selecting performed by the master station 1 only for each of the slave stations 201, 202, 203,. Station 20
When the control data is transmitted to 1, 202, 203,..., Only the control data is transmitted without transmitting the address data. However, when transmitting the control data, the master station 1 broadcasts each of the slave stations 201,
The reset signal is periodically transmitted to 202, 203,... To notify the start of the control data transmission.

The operation of the above configuration will be described. First, the master station 1 is connected to each of the slave stations 201 and 202 connected to the signal transmission path 3.
02, 203 ... are executed. This initial polling means that the master station 1 requests each of the slave stations 201, 202, 203,.
The absolute addresses set in advance to 2,203... Are sequentially transmitted.
1, 202, 203,... Indicate their own models and setting contents to the master station 1.
It is to return to.

The master station 1 counts the number of slave stations connected to the signal transmission line 3 based on the above-described initial polling, and then calculates the number of slave stations 20 existing on the signal transmission line 3.
, 202, 203,..., Successive relative addresses are transmitted by selecting from the smallest absolute address of each of the slave stations 201, 202, 203,.

Here, as shown in FIG. 1, the absolute address is a unique address set in advance by a switch or the like for each of the slave stations 201, 202, 203... 2n, and the relative address is a slave address. This is a temporary address that exists only for the number of the stations 2n.

When the setting of the relative address from the master station 1 to each slave station 2n is completed, the master station 1 transmits a reset signal on the signal transmission line 3 by broadcasting. The broadcast is a signal that must be received by all the slave stations 2n, and is generally a specific address (for example, “F”).
The address is controlled by transmitting control data following transmission of an address such as F ″. In this case, each of the slave stations 2 n receives a reset signal on the signal transmission line 3. When the communication is performed, preparations for receiving control data are started.

Subsequently, the master station 1 transmits control data to each slave station 2n. However, unlike the polling method, the master station 1 does not send an absolute address, and collects the control data of each slave station 2n in the order of relative addresses. The signals are collectively transmitted on the signal transmission path 3. That is, on the signal transmission path 3, FIG.
.., The maximum value of the relative addresses, that is, the control data for the number of slave stations 2n, is transmitted in the order of the relative addresses. .

In this case, FIG. 3 shows an example in which each slave station 2n sends 1-byte control data from the master station 1. However, the number of bytes of the control data is determined in advance as 2 bytes, 3 bytes, or the like. With this arrangement, it is possible to easily cope with the case where the amount of control data is increased.

The slave station 2n counts the data transmitted on the signal transmission line 3 after receiving the reset signal, and uses the control data corresponding to the predetermined relative address as the control data addressed to itself. Take in the station.

That is, the slave station 201 having a relative address of 1 receives the first 1 byte (or a plurality of bytes if predetermined) of the data transmitted on the signal transmission line 3 after receiving the reset signal. The slave station 202 whose relative address is 2 receives the data of the second byte. However, the number of bytes of the data to be received is set to be the same for each slave station 2n.

According to the above configuration, after the master station 1 detects the number and type of each slave station by initial polling, a continuous relative address is first allocated to each slave station 2n by selecting. When the control data is transmitted to the slave station 2n, the control data is collectively transmitted in the order of the relative addresses, thereby eliminating the need to transmit the absolute address from the master station 1 to each slave station 2n. Compared to a configuration in which control data is transmitted one by one by address-based selection, the data refresh time of the slave station 2n is reduced, and a controlled device connected to the slave station 2n can respond at high speed.

The relative address is added for each slave station 2n. However, when the number of bytes of control data addressed to each slave station 2n is individually different, a relative frame is used instead of a relative address. You can also handle it.

FIG. 4 shows a second embodiment of the present invention, in which the control data of the first slave station 201 is 1 byte, the control data of the second slave station 202 is 2 bytes, and the third is Even if the control data of the slave station 203 is different from the control data of the third slave station 204 by one byte or the control data of the fourth slave station by one byte,... At the time of selecting, a relative frame number is allocated to each slave station 2n, and all control data transmissions from the master station 1 are transmitted collectively, and each slave station 2n counts the number of transmitted control data frames. In this case, only the frame addressed to the user may be taken. In this case, the relative frame is the first slave station 20.
The first frame to be received should be the relative frame number, such as 1 for 1 frame, 2nd slave station 202 for 1 + 1 = 2 frames, 3rd slave station 203 for 1 + 1 + 2 = 4 frames, and so on. .

The present invention is not limited to the above embodiment, but can be modified or expanded as follows. In the first embodiment, the number of bytes of the control data addressed to each slave station 2n has been described as being predetermined. However, the master station or the slave station determines the number of bytes at the time of initial polling.
By specifying the number of bytes for each slave station at the time of the first selection, it is possible to cope with a change in the data amount.

[0030]

As is clear from the above description, the transmission apparatus of the present invention has the following effects. According to the first aspect, since the control data is transmitted and received from the master station to the slave station at a timing based on the relative address, the data refresh time of the control data to the slave station is shortened with a simple configuration. Thereby, the responsiveness of the controlled device connected to the slave station can be improved.

According to the second aspect, the master station can notify the slave station of the start timing of the control data by transmitting the reset signal by broadcast communication. The timing can be reliably recognized.

According to the third aspect, the master station transmits the control data addressed to each slave station collectively in the order of the corresponding relative addresses, so that the transmission time of the entire control data is greatly reduced. be able to.

According to the fourth aspect, when the slave station recognizes its own relative address by the relative address data addressed to each slave station by selecting, the control data addressed to itself from the next time on the basis of the relative address. The control data transmission time from the next time can be shortened.

According to the fifth aspect, when the control data is collectively transmitted from the master station, the slave station counts the number of control data transmitted, and controls the slave station at a timing based on the count value. Since the data is taken in, it is possible to take in the control data destined for itself without storing all of the control data from the master station.

[Brief description of the drawings]

FIG. 1 is a diagram showing a relationship between an absolute address and a relative address for each slave station in a first embodiment of the present invention.

FIG. 2 is a schematic diagram showing the overall configuration.

FIG. 3 is a diagram showing a relationship between a relative address and a transmission timing of control data.

FIG. 4 is a view corresponding to FIG. 3, showing a second embodiment of the present invention;

[Explanation of symbols]

1 is a master station, 201, 202, 203... 2n are slave stations, and 3 is a transmission line.

Claims (5)

[Claims] 1. A data transmission device for connecting a master station and a plurality of slave stations through a transmission path and controlling a controlled device connected to each slave station by the master station, wherein the master station first By transmitting consecutive relative address data to each slave station by selecting based on a preset absolute address to each slave station, a different relative address is assigned to each slave station, and then the relative address is determined at a timing based on the relative address. A data transmission apparatus for transmitting control data addressed to a slave station corresponding to an address, wherein the slave station takes in control data from the master station at a timing based on the assigned relative address. 2. When transmitting control data addressed to each slave station, the master station transmits a reset signal instructing the start of control data transmission by broadcast communication simultaneously received by the slave stations via the transmission path. The data transmission device according to claim 1, wherein the data transmission is performed. 3. The data transmission apparatus according to claim 1, wherein said master station transmits control data addressed to each slave station collectively in the order of the corresponding relative addresses. 4. The slave station, when recognizing its own relative address by selecting by the master station, fetches control data addressed to itself from the next time at a timing based on the relative address. 4. The data transmission device according to any one of claims 3 to 3. 5. The slave station counts the number of control data transmitted when the control data is transmitted collectively from the master station, and fetches control data addressed to itself at a timing based on the count value. The data transmission device according to claim 1, wherein: