JPH0442859B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for detecting the position of a host computer during image transfer, which is applied to a local area network system in which information is transmitted and received via a LAN bus.

[Technical background of the invention]

A ring bus system in which information is transmitted and received via a ring bus is generally configured as shown in FIG. In such a system, the ring bus 11 is equipped with various stations such as a monitoring station (hereinafter referred to as SVC) that monitors the entire system.
) 12 and normal station (hereinafter referred to as
(referred to as STN) 13 to 16 are connected. Information transfer between various devices such as computers and terminal devices connected to these STNs 13 to 16 is performed via the ring bus 11. The above-mentioned computers can be divided into lower-level computers, host computers, and higher-level computers depending on their configurations and roles.
Each computer will be explained below.

lower-order computer A computer without external storage.

Host computer A computer that has an external storage device and stores the main memory image of the lower-level computer in this storage device.

Host computer A computer with an external storage device. From this point of view, the host computer is also included in the upper level computer.

In Figure 1, 17 is a lower-order computer (hereinafter referred to as
(referred to as LCPU), 18 ₁ ~ 18 _o , 19,20 ₁ ~
20 _n and 21 are upper computers (hereinafter referred to as UCPUs). However, in FIG. 1, the UCPU 19 is a host computer (hereinafter referred to as HCPU), so it will be referred to as HCPU 19 instead of UCPU 19. Information transmission and reception called image transfer is performed between the LCPU 17 and the HCPU 19 as necessary. This image transfer will be explained below. Generally, when restarting an LCPU after it goes down for some reason, as the LCPU does not have an external storage device as mentioned above,
It is necessary to have the HCPU send the LCPU's main memory image. This operation of transmitting the main memory image from the HCPU to the LCPU is called downline loading. In addition, in order to investigate the cause of the LCPU going down on the HCPU side, the main memory image that the LCPU has at that point is transferred to the HCPU.
The operation of sending the data to the HCPU and having it saved in the external storage device of the HCPU is called an upline dump. Image transfer is a general term for upline dumping and downline loading.

When the above-mentioned image transfer request occurs in the LCPU 17, the ROM (Read Only Memory) 22 in which the image transfer program is fixedly stored
The image transfer program is read from. The LCPU 17 makes an image transfer inquiry to the HCPU according to this image transfer program. Since the LCPU generally does not know the location of the HCPU, it queries each UCPU in turn. UCPUs that are not designated as HCPUs do not return responses, and only UCPUs that are designated as HCPUs return responses, so the LCPU recognizes the UCPU that has returned a response as an HCPU and performs image transfer. i.e. LCPU1
7, as shown in the timing chart of FIG. 2, first makes an inquiry to the UCPU ₁₈₁ .
Thereafter, the LCPU 17 monitors the time until a response to the above inquiry is returned. and,
If no response is returned after a certain period of time T,
LCPU17 is the contact point (in this case UCPU18 ₁ )
is not an HCPU, and the next UCPU18 ₂
Make an inquiry to .

It is assumed that inquiries are made in this manner from UCPU 18 ₁ to UCPU 18 _o in order. UCPU1
Since 8 _o is not an HCPU, no response to the inquiry is returned from UCPU 18 _o . When the LCPU 17 detects that no response is returned even after a certain period of time T has elapsed after the inquiry, the LCPU 17 sends a response to the next UCPU, the HCPU 19.
Make an inquiry to . HCPU19 is LCPU1
In response to the inquiry from 7, a response is returned as shown in FIG. As a result, LCPU17 becomes HCPU
I was able to know the location of LCPU 19, and from now on, I was able to know the location of LCPU 17.
Image transfer between the HCPU 19 and the HCPU 19 becomes possible.

[Problems with background technology]

In this way, in a conventional ring bus system, when an image transfer request is made, the LCPU transfers information to each UCPU (including the HCPU as described above) until an HCPU is found.
UCPU) had to be queried sequentially. The above contact information is HCPU
Even if this is not the case, the user has to wait for the maximum amount of time (a certain time T) in hopes of receiving a response from the other party. For this reason, especially when there are many UCPUs,
The drawback was that it took a lot of time for the LCPU to search for the HCPU during image transfer.

[Purpose of the invention]

The present invention has been made in view of the above circumstances, and its purpose is to
An object of the present invention is to provide a method for detecting the position of a host computer during image transfer, which can significantly shorten the time required for a (lower-level computer) to search for an HCPU (host computer), thereby increasing the speed of image transfer.

[Summary of the invention]

While the HCPU defines in advance to the SVC that it is an HCPU, the LCPU queries the SVC when an image transfer request occurs, thereby preventing the SVC from making subsequent queries containing the LCPU's location information. This is done for the HCPU defined above, and the HCPU responds to the inquiry from the SVC.
By returning a response containing the HCPU's location information to the LCPU, the LCPU can learn the HCPU's location and perform image transfer.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. Note that the same parts as in FIG. 1 are given the same reference numerals and detailed explanations are omitted. In the ring bus system shown in FIG. 3, 30 is an HCPU (host computer). The HCPU30 has a system initialization routine (hereinafter referred to as INZ routine).
31 and SVC (viewing station) 50, which will be described later.
A host computer definition routine (hereinafter referred to as HCPU definition routine) 32 is provided for defining (registering) that the own computer is an HCPU. 40 is LCPU (low-order computer), 4
1 is a ROM provided in the LCPU 40.
The ROM 41 stores an image transfer program similarly to the ROM 22 in FIG. ROM4
The image transfer program stored in 1 is
It includes a step of making an image transfer inquiry to the SVC 50. 50 is SVC.
In addition to the well-known monitoring mechanism, the SVC 50 uses host computer definition information (hereinafter referred to as
HCPU definition information) and LCPU40
HCPU30 in response to an image transfer inquiry from
It has the function of making inquiries corresponding to the following.

Next, the operation of one embodiment of the present invention will be explained with reference to the timing chart of FIG. 4 as appropriate. In the initial state of the system, the INZ routine 31 is activated in the HCPU 30, and the HCPU 30 is initialized.
Next, the HCPU definition routine 32 is activated.
The HCPU 30 follows this HCPU definition routine 32 and defines that its own computer is an HCPU.
The HCPU definition information is transferred to the SVC 50 via the STN 15 and the ring bus 11 (see FIG. 4). SVC
50 stores the above-mentioned HCPU definition information. This definition information includes location information (station number, computer number) of the HCPU 30.

It is assumed that an image transfer request is generated in the LCPU 40 in such a state. As a result,
An image transfer program is read from the ROM 41, and this transfer program is stored in a predetermined area of a main memory (not shown) provided in the LCPU 40. The LCPU 40 uses the image transfer program to inquire about image transfer to the SVC 50 as shown in FIG. This inquiry information also includes location information of the LCPU 40.
When the SVC 50 receives the above inquiry information from the ring data bus 11, it
Based on the HCPU definition information, predetermined inquiry information is transmitted to the HCPU 30 as shown in FIG. This inquiry information includes information about the LCPU 40.

When the HCPU 30 receives the inquiry information from the SVC 50, it returns a response to the LCPU 40 based on the information about the LCPU 40 contained in this information (see FIG. 4). HCPU30 to LCPU40
The response information sent back includes location information of the HCPU 30, and the LCPU 40 can know the location of the HCPU 30 from the response information.
As a result, as shown in Figure 4, the LCPU40 and
Image transfer between the HCPU 30 and the HCPU 30 becomes possible.

In this way, according to this embodiment, the LCPU 40 has one
Just by querying the SVC 50 times,
You can search for HCPU30 in an extremely short time.
This is the same no matter where the HCPU 30 is located in the system, that is, no matter what system configuration. By the way, in the conventional system,
The number of inquiries varies depending on the positional relationship between the HCPU and LCPU and the positional relationship between the HCPU and UCPU. In addition,
In conventional systems, if the position of the HCPU is fixed, the number of inquiries can be reduced to, for example, once, but because the system is fixed, it lacks flexibility and cannot be freely configured. There is. In contrast, in this embodiment, the number of inquiries mentioned above is unrelated to the position of the HCPU, and the system configuration can be freely configured.

〔Effect of the invention〕

As detailed above, according to the method for detecting the location of a host computer during image transfer according to the present invention, the time required for the LCPU (low-order computer) to search for the HCPU (host computer) can be significantly shortened, thereby increasing the speed of image transfer. can be achieved.

[Brief explanation of drawings]

Fig. 1 is a system configuration diagram showing a conventional example, Fig. 2 is a timing chart for explaining the operation of the conventional example, and Fig. 3 is a system configuration diagram showing an embodiment of a ring bus system to which the present invention is applied. , FIG. 4 is a timing chart for explaining the operation of the above embodiment. 11... Ring bus, 12, 50... Monitoring station (SVC), 17, 40... Lower computer (LCPU), 18 ₁ to 18 _o , 20 ₁ to 20 _n , 21...
Upper computer (UCPU), 22, 41...ROM, 1
9, 30...Host computer (HCPU), 32...Host computer definition routine (HCPU definition routine).

Claims (1)

[Claims] 1 A local area network that has a LAN bus to which multiple stations, including a monitoring station that monitors the entire system, are connected, and that images are transferred between host computers and lower-level computers connected to the stations via this LAN bus. In the work system, means for the host computer to transfer host computer protocol information defining that the computer is a host computer to the monitoring station, and means for the monitoring station to save the host computer protocol information. and means for making an inquiry to the monitoring station to that effect in response to an image transfer request in the lower-level computer; and in response to the inquiry by the means, the monitoring station sends an inquiry to the host computer based on the host computer protocol information. The host computer includes means for transmitting inquiry information including location information of the lower-level computer to a computer, and means for causing the host computer to return a response to the lower-level computer based on the inquiry information including the position information of the lower-level computer. . A method for detecting the position of a host computer during image transfer, characterized in that the lower-level computer learns the position of the host computer by receiving a response from the host computer.