JPS60106248A - Control system for data transfer - Google Patents

Abstract

PURPOSE:To perform efficient data transfer by controlling the length of transfer data selectively according to the kind of an opponent device as an objective of communication. CONSTITUTION:When data transfer to and from a system Y is carried out, a request to set a bus is made with a frame of specific constitution prior to the transfer. This frame contains the kind of the device, so the system Y knows the kind of a device at transmission destination. When communication is allowed for the bus setting request, the system Y sends a bus setting perfmission signal with a frame of specific constitution. In this case, the device kind of the system Y is sent, so the device kind of the system Y is discriminated. Network controllers 11-13 retrieve a correspondence table of kinds of devices and transfer data lengths stored in a memory to know the transfer data length, thereby transferring data of the corresponding data length.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Technical Field of the Invention The present invention relates to data transfer via a communication path between information processing devices, and relates to the functions of a network control device.

(2) Prior Art and Problems Figure 1 is a diagram explaining data transfer between information processing devices, where II to 1 are information processing devices, 21 to 2I are network control devices (adapters), and 3 is a communication device. represents the road.

In a system like the one shown in FIG. 1, the data length of one frame divided by data transfer between conventional information processing devices takes a fixed value determined by the hardware of the network control device, or takes a fixed value determined by the hardware of the information processing device ( O8)
In the former fixed length method, data is transferred in a fixed length even if devices with different specifications and different transfer data lengths are mixed in the system. This has the drawback of poor efficiency in data transfer. In addition, in the latter method, in which the O8 of the information processing device transmits data in a variable length, the O8 must always recognize the type of device to be communicated with, and control may need to be changed depending on the other party. This has disadvantages in that the processing becomes complicated and the load on the information processing device increases.

(3) Purpose of the Invention In view of the above-mentioned drawbacks of the conventional art, the present invention is capable of transmitting data by changing the data length depending on the type of the communication destination device.
The purpose of the present invention is to provide a control system for data transfer that does not increase the load on an information processing device. As described, a plurality of information processing apparatuses are connected to a common circular communication channel via a network control apparatus, and the communication between any two of these information processing apparatuses is In a system that transfers data by setting a path on the road, the network control device is equipped with a means that can recognize the data length of one frame to be transferred depending on the type of the other device, and data transfer between information processing devices is performed. The feature is that each device notifies the other party of the type of its own device when setting a path prior to starting data transfer, and data transfer is performed using a frame with a data length corresponding to the type. This is achieved using a data transfer control method.

(5) Embodiment of the invention FIG. 2 is a diagram showing the frame structure of a path setting request or path setting permission according to an embodiment of the invention, where 4 is a delimiter (FS) indicating the beginning of the frame, and 5 is a transmission destination. Address (D
A), 6 is the source address (SA), 7 is the code indicating the path setting request frame or the code indicating path setting permission (CMD), 8 is the type of the own device (PARA),
9 is frame φ check sequence (Fe2), 10
represents a delimiter (FE) indicating the end of the frame. The path setting request frame and the path setting permission frame have different CMD codes of 7.

FIG. 3 is a flowchart showing one embodiment of the present invention, and shows control when a network control device transmits and receives data to and from a certain system (expressed as system Y in the figure).

In FIG. 3, when data is transferred to and from system Y, a bus setting request is made using a frame having the configuration shown in FIG. 2 prior to this. The frame has a second
As shown in FIG. 8, since the type of own device (CPARA) is included, system Y, which is the other party, can
You can know the type of device on this side (sending source).

In response to this path setting request, if communication is possible, system Y notifies the path setting permission using a frame having the configuration shown in FIG. In this case as well, the device type (PARA) of the sending side (system Y) is sent, so
This allows the device type of system Y to be determined. The network control device further searches a correspondence table of device type, transfer, and data length stored in the memory to learn the transfer data length, and thereby transfers data according to the corresponding data length. In Fig. 3, data is divided into IK bytes and transferred continuously (device type 1dA>:, data is transferred 4 bytes at a time (device type is B).
An example with two conditions is shown.

On the other hand, in the case of receiving data, the other party recognizes the type of device on the other side and transfers data with an appropriate data length, so the receiving process can be performed as is.

(6) As described in detail, according to the data transfer control method of the present invention, the network control device selectively controls the transfer data length depending on the type of the communicating partner device, so that efficient data transfer is possible. In addition, since data length selection etc. do not place any burden on the O8 of the information processing device that is the host, the processing related to communication in the OS is simplified and the load on the information processing device is reduced. It has great effects, such as increasing processing capacity.

[Brief explanation of the drawing]

FIG. 1 is a diagram explaining data transfer between information processing devices, FIG. 2 is a diagram showing a frame structure of a bus setting request or bus setting permission according to an embodiment of the present invention, and FIG.
It is a figure showing an example. 1, ~1. ...... Information processing device, 21-2
．． ......Network control device (adapter), 3...Communication path, 4...
Delimiter (FS) indicating the beginning of the frame, 5...
- Destination address (DA>, 6... Source address (SA), 7... Code indicating a path setting request frame or code indicating path setting permission ( CMD), 8... Type of own device (PARA) 9... Frame-check sequence (Fe2) 10... End of frame Delimiter (FE) agent that indicates ” Patent attorney Hiroshi Matsuoka

Claims (1)

[Claims] A plurality of information processing devices are each connected to a common circular communication channel via a network control device, and between any two of these information processing devices,
In the system that transfers data by setting a node on the communication path, the network control device is provided with a means for recognizing the data length of one frame to be transferred depending on the type of the destination device, and the information is transferred. When transferring data between processing devices, each party notifies the other party of the type of its own device at the time of setting the node before starting the data transfer, and the type is determined according to 91J. A data transfer finger control method characterized in that data is transferred using frames of a data length.