JPH0342026B2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention is directed to a data transmission device or the like connected to a common bus, in which a plurality of transmitting slave stations and receiving slave stations whose data transmission is controlled by a control station are connected to a common bus. This invention relates to improvement of multiplex transmission method between slave stations.

<Prior Art> An example of a conventional data transmission device is shown in FIG. 3, and a multiplex transmission method will be explained.

As shown in this figure, the control station C and the transmitting slave station
s ₁ , s ₂ , . . . , s _o and reception slave stations r ₁ , r ₂ , . . . , r _o are connected to a common bus B.

In addition, slave station address 1 is assigned to the transmitting slave station s ₁ and receiving slave station r ₁ , slave station address 2 is assigned to the transmitting slave station s ₂ and receiving slave station r ₂ , and slave station address 2 is assigned to the transmitting slave station s 1 and the receiving slave station r ₁ . A slave station address n is set for the reception slave station r _o by a dip switch or the like installed in each slave station.

In the conventional data transmission device configured in this way, as shown in the time chart of FIG.
is output, and the count corresponding to the slave station address is output.
Pulse cp and data information _d1 are output. That is,
The reset pulse rp from the control station C enables the data transmission device itself to transmit, and each slave station starts counting the count pulses cp from the control station C. Counted sending slave station s ₁ , receiving slave station r ₁
(Both slave station address; 1) becomes valid, and then data transmission information d ₁ is output from the control station (This data transmission information may be output from the control station or from the transmitting slave station itself) Depending on the transmitting slave station
_S1 outputs transmission data to receiving slave station _r1 for transmission.

Then, the next output count pulse cp
The transmitting slave station s ₂ that has counted the transmission data transmits the transmission data to the receiving slave station r ₂ in the same manner as described above.

The same operation is performed up to address n, one cycle is completed, and the control station C outputs a reset pulse rp.

In this way, in the conventional multiplex transmission method, data transmission is performed by making the transmitting slave station and the receiving slave station have the same slave station address, thereby making the slave stations correspond 1:1. Ta.

Note that this data transmission device may include a slave station having both transmitting and receiving functions.

However, in factories, for example, product assembly lines are often changed, and in conventional data transmission equipment, the address of each slave station must be It was necessary to set the same value using the dip switch installed in each slave station. Therefore, since humans change the address of each slave station using a dip switch, it is necessary to install the slave stations in locations that are accessible to humans. This makes it difficult to match the transmitting slave stations with the receiving slave stations.

<Problems to be Solved by the Invention> The problems to be solved by the present invention are to perform the correspondence between a transmitting slave station and a receiving slave station through operations on the control station side. The purpose is to facilitate address change operations.

<Means for Solving the Problems> The present invention for solving the above problems is as follows.

That is, in a multiplex transmission method for a data transmission device having a control station and a plurality of transmitting slave stations and receiving slave stations connected to a common bus and whose data transmission is controlled by the control station, A memory table capable of storing transmission information from the outside is provided in the device, a fixed address is set for each of the plurality of transmitting slave stations and receiving slave stations, and when data is transmitted, a memory table is provided that can store transmission information from the outside. transmission data is stored in the memory table, and the stored transmission data is transmitted to a designated reception slave station according to the transmission information stored and stored in the memory table. This is a multiplex transmission method.

<Operation> According to the multiplex transmission method of the present invention, the following operations are performed.

Different unique addresses are set for the transmitting slave station and the receiving slave station, and during data transmission, data information from the transmitting slave station is temporarily stored in a memory table inside the control station. In this memory table, transmission information such as a sending slave station address and a receiving slave station address can be set from the outside, and data transmission between slave stations is performed according to the transmission information in this memory table. .

<Embodiment> FIG. 1 shows a block diagram of an example of an optimal data transmission apparatus for carrying out the multiplex transmission method of the present invention.

In this figure, inside the control station C, there is a memory table c ₁ and a memory table in which the data transmission information and the transmission information transmitted from the transmitting slave station are stored.
c Central processing unit that stores and stores information in ₁
It is composed of a CPU c ₂ , a transmission control section c ₃ that generates a reset pulse rp, and a count pulse CP to control transmission. The central processing unit CPUc ₂ is connected to an input device 10 such as an external man-machine interface.
The transmission information is set in the memory table c ₁ based on the information from the control station C, and the transmission information is also set in the memory table c ₁ from the external computer 20 by the communication means c ₄ inside the control station C. can do.

When carrying out the multiplex transmission method of the present invention, transmitting slave stations s ₁ , s ₂ , ... _so and receiving slave stations r ₁ , r ₂ ,
..., r _o , its slave station address is
Depending on the switch 1, 2,..., n, n+1, n+
2, . . . , n+n, and a fixed address is set for each slave station. The number of transmitting slave stations and the number of receiving slave stations do not particularly need to match.

Here, the internal configuration diagram of the memory table _c1 in the control station C is shown in FIGS. 2a and 2b.

The case where the configuration of memory table _c1 is shown in FIG. 2a will be explained.

In the case of Fig. 2 a, memory table c ₁ contains transmission slave station addresses 1, 2, ..., n as transmission information.
and receiving slave station addresses n+1, n+2, which are the destinations of data transmission information transmitted from the transmitting slave stations.
..., n+n are set in advance. This setting operation is performed using an external man-machine interface input device 10. Then, the data transmission information d ₁ transmitted from the transmitting slave station s ₁ of the slave station address 1, which was made valid by the count pulse cp from the control station C, is transferred to the area of the transmitting slave station address 1 by the CPUc _2. Next, data transmission information d ₂ from the transmitting slave station with slave station address 2, and data transmission information d ₂ , ..., d _o from the transmitting slave station with slave station address n are stored and stored sequentially. be done.

Once all of these data transmission information d ₁ , d ₂ , ..., d _o are stored in the memory table c ₁ , the transmission control unit c ₃ stores the data transmission information d ₁ , d o transmitted from the transmitting slave station. ₂ ,...,d _o as the receiving slave station corresponding to each transmitting slave station (slave station address n+1, n+2,..., n+
transmission starts at n).

In this way, since the slave station addresses of the transmitting slave station and the corresponding receiving slave station are stored in advance in the memory table as transmission information, the transmission control unit _c3 refers to this while performing the following operations. Corresponding data transmission information can be transmitted sequentially.

FIG. 2b shows a case where the external computer 20 uses this memory table _c1 as a storage device via the communication means _c4 . That is, the memory table _c1 contains the slave station address table (1, 2,...,
n, n+1, n+2, . . . , n+n) are set, and the transmission information d ₁ , d _{2 .} That is, in the transmission cycle, the data transmission information d1 sent from the sending slave station address ₁ is stored in the data column of the sending slave station address 1 as the sending slave station address 2.
The data transmission information _d2 transmitted from the slave station address 2 is sequentially written into the data column of the slave station address 2. Then, the external computer specifies the slave station address of the receiving slave station corresponding to the transmitting slave station, and data is transmitted to the receiving slave station only after this address designation operation.

In the example shown in this figure, the receiving slave station is designated by the external computer 20 as the transmitting slave station with slave address 1, and the transmitting slave station with slave address 2 is designated as the receiving slave station by the external computer 20. In this example, the receiving slave station is specified as the slave station with the slave station address n+2, and if the receiving slave station does not receive data, for example, "*" is specified.
Set symbols such as.

When data transmission information d1 of slave station address ₁ is written in a predetermined data column, and the slave station for receiving this data transmission information is designated by the computer as n+1,
Data transmission information _d1 is written in the slave station address n+1 column of the memory table. When all of the data columns are written by sequentially performing such operations, the data transmission information is sequentially transmitted from the slave station having the reception slave station address n+1.

If you do this, the transmitting slave station will be the external computer 2.
The input device to 0 and the reception slave station can be used as an output device of the external computer 20.

As described above, transmission can be performed by fixing unique addresses to the transmitting slave station and the receiving slave station, so there is no need to provide a 1:1 correspondence between the transmitting slave station and the receiving slave station. do not have.

<Effects of the Invention> According to the multiplex transmission method of the present invention, correspondence between a transmitting slave station and a receiving slave station can be performed entirely by operations on the control station side, making it easy to change addresses of slave stations. Therefore, it is possible to easily change the product assembly line at the factory.

[Brief explanation of drawings]

Figure 1 is a block diagram of a data transmission device for explaining the multiplex transmission method of the present invention, Figures 2a and b are configuration diagrams of a memory table inside the control station, and Figure 3 shows the conventional multiplex transmission method. FIG. 4 is a block diagram of the data transmission device for explanation, and is a time chart showing pulse output for controlling the slave stations of the control station. s ₁ , s ₂ , ~, s _o ... Transmission slave station, r ₁ , r ₂ , ~, r _o
...Slave station for reception, C...Control station, c ₁ ...Memory
table, c ₂ ... central processing unit CPU, c ₃ ... transmission control section, c ₄ ... communication means, 10 ... input device, 20
……calculator.

Claims (1)

[Claims] 1. In a multiplex transmission method for a data transmission device having a control station and a plurality of transmitting slave stations and receiving slave stations connected to a common bus and whose data transmission is controlled by the control station, A memory table capable of storing transmission information from the outside is provided, a fixed address is set for each of the plurality of transmitting slave stations and receiving slave stations, and when data is transmitted, information from the transmitting slave station is set. A multiplex system characterized in that transmission data is stored in the memory table, and the stored transmission data is transmitted to a designated receiving slave station according to the transmission information stored and stored in the memory table. Transmission method.