JPH04255048A - Data communication speed switching system - Google Patents

Abstract

PURPOSE:To optionally and simultaneously switch the data communication speeds of a master computer and a slave computer without stopping a system by switching respective communication speeds by using a communication speed switching instruction. CONSTITUTION:A data communication speed switching request receiving circuit 11 in the master computer 1 applies a data communication speed switching request inputted from a maintenance terminal 10 to a data communication speed switching informing circuit 12. The circuit 12 informs data communication speed switching to a response circuit 20 in the slave computer 2. After returning a data communication speed switching preparation completion response from the circuit 20 to the circuit 12, a data communication speed switching circuit 21 switches the data communication speed of the slave computer 2. The circuit 12 informs the data communication speed switching to a data communication speed switching circuit 13 based upon the switching preparation completion response applied from the slave computer 2. Then the circuit 13 switches the data communication speed of the master computer 1.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data communication speed switching system between computers in a master-slave relationship.

0002

2. Description of the Related Art Conventionally, data communication is performed between computers in a master-slave relationship at a unique data communication speed determined at the time of system construction.

0003

[Problem to be Solved by the Invention] In the conventional data communication between computers in a master-slave relationship as described above, the data communication speed is a unique value, so the data communication speed is changed depending on the convenience of the maintainer. In this case, it would be necessary to stop the main computer and the slave computer separately and change the data communication speed defined as a system constant, which caused problems in system operation.

0004

[Means for Solving the Problems] The data communication speed switching method of the present invention includes means for simultaneously switching the data communication speeds of the main computer and the slave computer by giving a data communication speed switching instruction from the main computer to the slave computer. We are prepared.

[0005] The main computer also includes a switching request reception circuit that receives a data communication speed switching request from a maintenance person, a first switching circuit that switches a data communication speed constant of the main computer, and a data communication speed constant that changes the data communication speed to the slave computer. a switching notification circuit that notifies the switching, and the slave computer includes a response circuit that responds to the data communication speed switching notification from the main computer, and a second switching circuit that switches the data communication rate constant of the slave computer. It is equipped with

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the data communication speed switching system of the present invention. Figure 1 shows the main computer 1
This shows a system in which data communication is carried out between a slave computer 2 and a slave computer 2.

In the main computer 1, a data communication speed switching request receiving circuit 11 sends a data communication speed switching request input from a maintenance terminal 10 by a maintenance person to a data communication speed switching notification circuit 12. The data communication speed switching notification circuit 12 notifies the response circuit 20 of the slave computer 2 of the data communication speed switching. The response circuit 20 is the main computer 1
After returning a data communication speed switching preparation completion response to the data communication speed switching notification circuit 12 of the computer, the data communication speed switching circuit 21 switches the data communication speed of the slave computer. In the main computer 1, the data communication speed switching notification circuit 12 notifies the data communication speed switching circuit 13 of the data communication speed switching in response to the data communication speed switching preparation completion response from the slave computer 2. Data communication speed switching circuit 1
3 switches the data communication speed of the main computer 1.

Note that the data communication speed switching notification and the data communication speed switching preparation completion response between the main and slave computers 1 and 2 are performed via the data communication line used for normal data communication.

0010

[Effects of the Invention] As explained above, in the present invention, the data communication speeds of the main computer and the slave computer are simultaneously switched while online by a data communication speed switching notification from the main computer, so that it is possible to stop the system. This has the effect that the data communication speeds of the main computer and the slave computer can be switched simultaneously without any restrictions.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of a data communication speed switching system of the present invention.

[Explanation of symbols]

1 Main computer 2 Slave computer 10 Maintenance terminal 11 Data communication speed switching request reception circuit 12
Data communication speed switching notification circuit 13, 21 Data communication speed switching circuit 20 Response circuit

Claims (2)

[Claims] 1. A data communication speed switching system, comprising means for simultaneously switching data communication speeds between the main computer and the slave computer by giving a data communication speed switching instruction from the main computer to the slave computer. 2. The main computer includes a switching request receiving circuit that receives a data communication speed switching request from a maintenance person, a first switching circuit that switches a data communication speed constant of the main computer, and a switching request receiving circuit that receives a data communication speed switching request from a maintenance person; a switching notification circuit that notifies the switching, and the slave computer includes a response circuit that responds to the data communication speed switching notification from the main computer, and a second switching circuit that switches the data communication rate constant of the slave computer. 2. The data communication speed switching system according to claim 1, further comprising the following.