JPH03125532A - Down-load system for multi-point communication system - Google Patents

Abstract

PURPOSE:To improve the transmission efficiency by setting a secondary station designation flag designating a secondary station receiving down-load data to an information field and varying a byte length of the secondary station designation flag in response to number of nodes (secondary stations). CONSTITUTION:Since secondary station designation flags 8a, 8b designating a secondary station receiving down-load data 9a, 9b simultaneously are added before the down-load data 9a, 9b sent from a primary station, each secondary station discriminates whether or not it processes down-load data 9a, 9b. Since 1st flags 7a, 7b representing the presence of the secondary station designation flags 8a, 8b are added before the secondary station designation flags 8a, 8b and the resulting data is sent, when a secondary station receiving data does not exist, it is sent by using the 1st flags 7a, 7b. Furthermore, since a 1st data representing the byte length of the secondary station designation flags 8a, 8b is added before the secondary station designation flags 8a, 8b and the result is sent, the byte length of the secondary station designation flags 8a, 8b is freely changed. Thus, the transmission efficiency is improved.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a download method for a multipoint communication system in which a plurality of terminals are connected to one line, and in particular, the present invention relates to a download method for a multipoint communication system in which a plurality of terminals are connected to one line, and in particular, it is The present invention relates to a duran load method for a multipoint communication system of an FA (factory automation) system.

[Conventional technology]

In a control system such as an FA system, a self-controller serving as a primary station is connected to a plurality of secondary stations such as a numerical control device, a robot control device, a PC (programmable controller), etc. via a transmission path.

To download data between these terminals, a high-level data link control procedure (HDl, , C) that enables one-to-N communication is used.

This HDLC consists of frames consisting of a start flag sequence, address sequence, control field, data information, frame check sequence, and end flag sequence. This frame is a bit string that begins with a start flag sequence and ends with an end flag sequence.

Both the start flag sequence and the end flag sequence are composed of 8 bits of "01111110". The address field consists of 8 bits, and the address of the receiving station or the address of the transmitting station is set therein. Control field is 8
It consists of bits and sets the type of command or response. Various data are set in the information field. Frame check sequences are used to detect communication abnormalities.

[Problem to be solved by the invention]

In an FA system or the like configured with a multipoint communication system, the same data is often downloaded from a self-controller, which is a primary station, to a numerical control device, a robot control device, or the like, which is a secondary station.

However, if data is downloaded to multiple secondary stations using HDLC, frames with the same data (information field) must be transmitted for the same number of secondary stations, which reduces the efficiency of system data transmission. It was not very desirable.

The present invention has been made in view of these points, and an object of the present invention is to provide a download method for a multipoint communication system that achieves high transmission efficiency when downloading the same data to multiple secondary stations. shall be.

[Means to solve the problem]

In the present invention, in order to solve the above problems, one line is connected to one line.
In a download method of a multipoint communication system in which a next station and a plurality of secondary stations are connected, a secondary station that specifies the secondary station that simultaneously receives the download data before the download data transmitted by the primary station A station designation flag is added, and the second station designation flag is added before the secondary station designation flag.
A download method for a multipoint communication system is provided, characterized in that a first flag indicating the presence or absence of a next station designation flag and first data indicating a byte length of the secondary station designation flag are added and transmitted. .

Since a secondary station designation flag is added before the download data transmitted by the primary station to specify the secondary station that will receive the download data at the same time, each secondary station can determine whether or not it will process the download data. can be judged. Also, since the first flag indicating the existence of the secondary station designation flag is added before the secondary station designation flag and transmitted, if there is no secondary station that receives the download data at the same time, the first This can be sent by the flag. Furthermore, since the first data indicating the byte length of the secondary station designation flag is added before the secondary station designation flag and transmitted, even if the number of secondary stations is changed, the secondary The byte length of the station designation flag can be changed freely. This allows a plurality of secondary stations to simultaneously receive download data, and also eliminates the need to transmit a secondary station designation flag when not receiving the data simultaneously, thereby increasing transmission efficiency.

[Effect]

〔Example〕 An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a diagram schematically showing an FA system configured with a multipoint communication system, which is an embodiment of the present invention.

In the multipoint communication system of this embodiment, the self-controller 10 is the primary station, and the CNCs 20 and 30,
The robot control device 40 and PC 50 serve as secondary stations and
It constitutes the A system.

The self-controller 10 has an interface (INT) 1
1 via local area network (LAN>6
0 node 61.

Numerical control units (CNC) 20 and 30 are connected to the LAN 60 via interfaces (INT) 21 and 31, respectively.
are connected to nodes 62 and 63 of. The robot control device 40 communicates with the LA via an interface (INT) 41.
It is connected to node 64 of N60. The programmable controller (PC) 50 is an interface (INT)
51 to a node 65 of the LAN 60.

The self-controller IO receives a production command from a host computer (not shown) and transmits various data such as the machine program and the number of workpieces to the CNCs 20 and 30 of the secondary stations. For example, robot control data such as a workpiece attachment/detachment command is transmitted to the robot control device 40, and P
Control programs and the like corresponding to the devices that it controls are transmitted to the C50.

The self-controller 10 transmits various data to the secondary station and at the same time transmits the operating status of the secondary station to the host computer. That is, the self-controller 10 has CNCs 20 and 30, which are secondary stations, a robot control device 40, and a PC.
50, and when the operation is stopped or an abnormal state occurs, the state is transmitted to the host computer and displayed on the display screen. Further, the self-controller IO transmits necessary diagnostic data to the secondary station in an abnormal state, or transmits an abnormality processing cancellation program, etc.

FIG. 1 is a diagram showing the structure of a transmission frame used in the download method of the multipoint communication system of the present invention.

The start flag sequence 1, address field 2, control field 3, frame check sequence 5 and end flag sequence 6 in the frame are comprised of conventional HDLC.

In this embodiment, special data is set in the first part of the information field 4 where loading data is stored. That is, the first pie of information field 4) 7a
and 7b are used as a flag indicating the presence or absence of the secondary station designation flags 83 and 8b, and data indicating the byte length of the secondary station designation flags 8a and 8b.

Specifically, the most significant bit (MSB) A of the first 1 pie) 7a and 7b is a flag indicating the presence or absence of the secondary station designation flags 8a and 8b, and when the most significant bit A is "1", 2 Indicates that the next station designation flags 8a and 8b are present,
When it is “0”, it indicates that it does not exist. That is, the first 1
pie)? The most significant bits Δ of a and 7b serve as bits for determining the presence or absence of a secondary station designation flag.

Next, the 7 bits B to H following the most significant bit (MSB) A
is data indicating the byte length of the secondary station designation flags 8a and 8b. The byte length of the secondary station designation flags 8a and 8b is a value determined by the number of secondary station nodes. Therefore, 2
If the number of nodes at the next station is 1 to 8, the length is 1 byte, and 9 to 1
In the case of 6, a 2-byte length is assigned to the secondary station designation flag, and in the case of 17 to 24, a 3-byte length is assigned to the secondary station designation flag.

In the first byte 7a, the bit G is "1", indicating that the byte length of the secondary station designation flag 8a is 2 bytes, and in the first byte 7b, bit H is "1".
This indicates that the byte length of the secondary station designation flag 8b is 1 byte.

Each bit of the secondary station designation flags 8a and 8b
It is assigned according to the next station. Therefore, the secondary stations whose corresponding bits of the secondary station designation flags 8a and 8b are "l" process the download data 9a and 9b in the information field 4, and the secondary stations whose corresponding bits are "0" The station is download data 9
Processes a and 9b are not performed.

In the secondary station designation flag 8a, 1.2.5.7.9.10
．． Since the 11th flag is "1", the secondary station corresponding to that flag processes the download data 9a. In the secondary station designation flag 8b, the secondary station corresponding to the 1st, 2nd, 4th, or 5th flag processes the download data 9b.

In the embodiment shown in FIG. 1, the case where the highest pitch A of the first one pie) 7a and 7b is "1" has been explained, but if the highest pitch A) is "0", the secondary station Specified flag 8a
and 8b do not exist, and all bits following the first byte 7a and 7b become download data 9a and 9b. The receiving station at this time is determined by the address field 2 designation.

FIG. 3 is a diagram showing a flowchart of received data processing at the secondary station. In the figure, the number following S indicates the step number.

[S1] All secondary stations determine whether the most significant bit A of information field 4 is "l".

If it is "1", the process advances to S2; otherwise, the process ends without processing the downloaded data.

[S2] Most significant bit) If A is "1", each secondary station determines whether the corresponding bit of the secondary station designation flag 8a or 8b is "1". If the corresponding bit is "1" The secondary stations proceed to S3, and the other secondary stations end without processing the downloaded data.

[S3] The secondary station whose corresponding bit is 1'' processes the download data.

By adopting the download method of the multipoint communication system described above, when transmitting the same download data to multiple secondary stations, the primary station can transmit the same download data to multiple secondary stations by just polling once. It becomes possible to transmit download data to a predetermined station.

In addition, the nodes that make up the multipoint communication system (
Since the byte length of the secondary station designation flag can be varied depending on the number of secondary stations (secondary stations), the transmission efficiency 1 2 can be further improved.

〔Effect of the invention〕

As explained above, according to the present invention, a secondary station designation flag that designates the secondary station to be downloaded is set in the information field, and the secondary station designation flag is further set according to the number of nodes (secondary stations). By making the byte length variable, it has become possible to significantly improve transmission efficiency when transmitting the same download data to multiple secondary stations.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of a transmission frame used in the download method of the multipoint communication system of the present invention. FIG. FIG. 3 is a flowchart of received data processing at the secondary station. 6 8a, 8b 9a, 9. b 0 20.30 0 0 11.21.3 61.62.6 Flag Sequence Address Field Control Field Information Field Frame Check Sequence Secondary Station Designation Flag Download Data Self Controller NC Robot Control Device C 1,4151 Interface 3.64. 65 nodes

Claims (3)

[Claims] (1) In a download method of a multipoint communication system in which a primary station and a plurality of secondary stations are connected to one line, the download data is simultaneously received before the download data transmitted by the primary station. A secondary station designation flag that designates a secondary station is added, and a first flag indicating the presence or absence of the secondary station designation flag and a byte length of the secondary station designation flag are added before the secondary station designation flag. A download method for a multipoint communication system, characterized in that first data shown in the figure is added and transmitted. (2) The first flag consists of 1 bit, and the first
2. The download system for a multipoint communication system according to claim 1, wherein the data consists of 7 bits following the first flag. (3) The download method for a multipoint communication system according to claim 1, wherein each bit of the secondary station designation flag corresponds to each of the secondary stations. (4) The secondary station processes the download data only when the first flag exists and the corresponding bit of the secondary station designation flag exists. Download method of the multipoint communication system described in Section 2.