JPH0668013A - Advance control method for standard input/output interface based on rqi of input/output device - Google Patents

Abstract

PURPOSE:To eliminate the delay time by transmitting the change of a signal from a channel device to a second intermediate device on the input/output device side and reproducing an input/output interface signal on an input/output interface to transmit it to the input/output device. CONSTITUTION:If it is judged that a command chain is not continuous, a second intermediate device 31 terminates the preceding interface work, and a channel device 1 and a first intermediate device 30 which receive the status-in (STI) take in the input/output interface based on this STI. The channel device 1 sends only a service-out indication (SVO or SVO+SPO) for STI to the second intermediate device 31. If it is judged that the command chain sequence is continuous in a connection request (RQI) sequence, the input/output interface taking-in work is performed between the second intermediate device 31 and an input/output device 2 based on the service-out indication (SVO or SVO+SPO) from the channel device 1.

Description

Detailed Description of the Invention

[0001]

[Industrial field of application] With the recent spread of data processing by computer systems, computerization of office work is also progressing in rural areas. In this case, an expensive computer system is not installed in rural areas, and a terminal device is used. Only the (printer device, etc.) is connected and the central computer system is connected by a line.

This is due to the fact that high-speed lines have become available with the progress of line technology, but a predetermined tag is provided in the input / output interface for connecting the channel device of the computer system main body and the input / output device. There is a time constraint associated with the transfer of signals, which is a factor that limits the connection distance.

With the recent rise in land prices, a terminal system is placed in the center where the land prices are expensive, and a main unit is installed in a rural area where the land prices are low to construct a computer system. In response to such a demand, conventionally, an intermediate device for converting an input / output interface signal connecting a channel device and a plurality of input / output devices into a serial signal and extending a connection distance has been provided. In order to extend the communication distance, the number of responses of the input / output interface signal between the channel device and the input / output device appears as a product of delay times,
This is a factor that greatly reduces the installation distance.

Under such circumstances, the reason why an input / output interface control method capable of extending the installation distance is required.

[0005]

2. Description of the Related Art FIGS. 4 and 5 are views for explaining a long-distance communication means of a conventional input / output interface.
Shows an example of the connection configuration, Fig. 4 (b) shows an example of the exchange of input / output interface signals at the time of connection request (RQI) from the input / output device, and Fig. 5 (c) shows the conventional input / output interface signals. The operation time chart is shown.

Conventionally, intermediate devices 30, 31 for converting an input / output interface signal for connecting the channel device 1 and a plurality of input / output devices 2 and extending the connection distance are known, and FIG. Are connected as shown in. Here, the intermediate device on the side of the channel device 1 is called a first intermediate device, and the intermediate device on the side of the input / output device 2 is called a second intermediate device.

In this case, between the channel device 1 and the first intermediate device 30, or between the second intermediate device 31 and the input / output device 2, for example, an 8-bit bus line and a plurality of lines are provided. And the parallel line of the first intermediate device.
It is converted into a serial signal in 30 and sent to a predetermined high speed line, converted into an original parallel bus signal and a tag signal in the second intermediate device 31, and exchanged with the input / output device 2. It was

FIG. 4B shows a connection request from the input / output device 2.
An example of input / output interface signal exchange when (RQI) is transmitted is shown. First, the input / output device 2 receives an attention request by pressing the Enter key, a connection request accompanying the device end (DE) at power ready, a connection request accompanying the device end (DE) when data transfer is completed, etc. When the request-in (RQI) is activated from the output device 2, the select-out (SLO) is issued from the channel device 1, and when the input-output device 2 receives the select-out (SLO), the request-in (RQI) The signal is dropped, the operational in (OPI) and the address in (ADI) are sent out, the command output (CMO) is sent out from the channel device 1 as a response signal, and the I / O device 2 is sent in response to it.
Drops the above address in (ADI), and
Send (STI).

The status in (STI) channel device 1
Is received, the response is Select Out (SLO)
Service (SVO) from channel device 1
Command, or a suppress out (SPO) instruction to instruct the command chain from the channel device 1 is output, and the input / output device 2 that recognizes that the channel device 1 has dropped the select out (SLO) Inn (O
PI) The signal is dropped and the operation corresponding to the instruction from the channel device 1 is performed.

Address-in (AD
Corresponding to I) and status in (STI), the address (ADD) and status (##, DE, DE + SM) signals are carried on the bus line.

FIG. 5 (c) shows the input / output device 2, the second intermediate device 31, the line, and the first intermediate device when the request-in (RQI) signal is sent from the input / output device 2. Equipment 3
0 schematically shows transmission / reception of the input / output interface signal between 0 and the channel device 1.

In the conventional method, as shown in FIG. 5 (c), each input / output interface signal is transmitted to the channel device 1
Between the input / output device 2 and the input / output device 2 via the first intermediate device 30 and the second intermediate device 31.

[0013]

Therefore, as described above, in order to extend the communication distance, the number of responses between the channel device 1 and the input / output device 2 is the product of the delay times proportional to the communication distance. Appears as a factor that greatly reduces the installation distance.

Specifically, for example, in the channel device 1, after receiving a request-in (RQI) signal from the input / output device 2, a timer (not shown) is started and a service-out (SVO) signal is output. The time until the completion is counted, and there is a problem that a timer-out error occurs if the communication distance between the channel device 1 and the input / output device 2 is long.

Further, if the monopolization time of the input / output interface per one input / output device 2 increases, the processing of the other input / output device 2 cannot be performed, which has been a factor of degrading the performance of the computer system.

In view of the above-mentioned conventional drawbacks, the present invention provides a control method for a standard input / output interface by request-in (RQI) of an input / output device, which can economically eliminate a delay time due to a connection distance. The purpose is to do.

[0017]

1 and 2 are explanatory views of the principle of the present invention. The above-mentioned problems are solved by the prior control method of the standard input / output interface by the request-in (RQI) of the input / output device configured as follows.

In the first intermediate device 30 and the second intermediate device 31 for long-distance installation of the input / output interface connecting the channel device 1 and the plurality of input / output devices 2, the second intermediate device 31 is the input device. The work of fetching the status of the input / output interface by the connection request (RQI) from the output device 2 is started prior to the operation of the channel device 1, and the contents of the status are judged by the second intermediate device 31. , If the status is device end (DE), or device end (DE) + status qualifier (SM), it is judged that the command chain may continue, and if it is any other status, the command chain , The status in (STI) is transferred to the first intermediate device 30 on the channel device side, and in the above judgment, it is determined that the command chain does not continue. When it is,
The second intermediate device 31 finishes the preceding interface work, and the channel device 1 and the first intermediate device 30 which have received the status in (STI), input / output interface based on the status in (STI). The channel device 1 fetches the status of SVO, or SV, or SV
(O + SPO) is sent to the second intermediate device 31, and when it is determined in the above determination that the command chain sequence follows the connection request (RQI) sequence, it is input as the second intermediate device 31. The input / output interface is loaded with the output device 2 based on a service-out instruction (SVO or SVO + SPO) from the channel device 1.

[0019]

That is, in the transmission / reception of the input / output interface signal of the present invention, the first intermediate device on the side of the channel device detects the change of the signal from the channel device on the input / output interface by the first intermediate device. Using the long-distance communication means by the device (specifically, the same as the conventional one, serial signal means),
The information is transmitted to the second intermediate device on the input / output device side, and the input / output interface signal is reproduced on the input / output interface and transmitted to the input / output device according to the information received through the long distance communication means.

With respect to the input / output interface signal from the input / output device side, the second intermediate device to the first input device are similarly processed.
To the channel device through the intermediate device. In the above request-in (RQI) process of the I / O device, the response from the channel device to the status-in (STI) sent from the I / O device may be terminated with a service out (SVO) response. The command chain may be instructed by responding with the service out (SVO) + suppress out (SPO), but whether the response to this status in (STI) is completed or the command chain is Only can know.

However, the fact that the command chain does not continue next may be judged by the second intermediate device depending on the contents of the status in (STI) sent from the input / output device.

That is, there is a possibility that a command chain may follow the status in (STI) of the request in (RQI) because the status in (STI) is the device end (DE) + status qualifier (SM). ) Or a device end (DE) status, in the present invention, a sequence of request-in (RQI) in which the command chain may not continue (FIG. 1).
Then, in the case of status-in (STI) (##)}, the second intermediate device on the input / output device side takes in the input / output interface prior to the response of the channel device. In view of the fact that no problem occurs, the preceding control is performed.

A first intermediate device on the side of the channel device,
The input / output interface signals are exchanged with the second intermediate device on the input / output device side, and the status in (STI) is exchanged, and the service out is a response from the channel device to the status in (STI) signal. (SVO) or Service Out (SVO) + Suppress Out (SPO) only to minimize the transfer of serial signals between the first intermediate device and the second intermediate device. Therefore, it becomes possible to use it for input / output interface processing by another input / output device between the first intermediate device and the second intermediate device.

Therefore, the number of responses of the input / output interface signal between the first intermediate device and the second intermediate device can be reduced, and the performance of the computer system can be improved. Also, the required request-in (RQI) from the input / output device
However, the possibility of getting stuck due to the influence of other input / output devices (specifically, the exclusive use of the input / output interface) is reduced, and from this aspect, the performance of the computer system can be improved.

[0025]

Embodiments of the present invention will be described in detail below with reference to the drawings. 1 and 2 described above are explanatory views of the principle of the present invention.
1 shows a case where there is no command chain instruction, FIG. 2 shows a case where there is a command chain instruction, and FIG. 3 shows
It is the figure which showed one Example of this invention with the flowchart.

In the present invention, when the standard input / output interface is controlled by the request in (RQI) of the input / output device 2, the status in (S) of the request in (RQI) is controlled.
There is a possibility that the command chain may follow the (TI), the status in (STI) is the device end (DE) +
Paying attention to the case where there are two types of status, status modifier (SM) or device end (DE),
Request-in that the command chain may not continue
(RQI) sequence {Status 1 (STI) in Fig. 1
In the case of (indicated by (##)}, the second intermediate device 31 on the input / output device side 2 precedes the response of the channel device 1 to capture the input / output interface, and The first intermediate device 30 on the device 1 side and the input / output device 2
The exchange of the input / output interface signal with the second intermediate device 31 of the side is exchanged with the exchange of the above status in (STI),
The means for only service out (SVO), which is a response from the channel device 1 to the status in (STI) signal, or service out (SVO) + suppress out (SPO),
It is a necessary means for carrying out the present invention. The same reference numerals indicate the same objects throughout the drawings.

Referring to FIGS. 1, 2 and 4 (a), the standard input / output interface by the request-in (RQI) of the input / output device 2 of the present invention will be described with reference to FIG. The control method will be described.

First, the input / output device 2 outputs a request-in (RQI) signal associated with an attention request or the like.
In the input / output interface processing according to the present invention, the select-in (SLO) from the channel device 1 for the request-in (RQI) signal, the operational-in (OPI) from the input / output device 2, and the address-in (ADI) transmission, From the channel device 1, the command output (C
MO), and in response, the I / O device 2 drops the address-in (ADI) and sends the status-in (STI) as a sequence, prior to the operation of the channel device 1. And the second intermediate device 31 to transmit only the status-in (STI) signal from the second intermediate device 31 to the channel device 1 via the first intermediate device 30. {Refer to processing step 100 in FIG. 3} At this time, in the present invention, it is possible that the command chain may follow the status-in (STI) of the request-in (RQI) is the status-in (STI). Is a device end (DE) + status qualifier (SM) or a device end (DE) status. In the case of the (RQI) sequence {indicated by status-in (STI) (##) in FIGS. 1 and 3}, the second intermediate device 31 on the input / output device side 2 is the channel device 1). The input / output interface is captured prior to the response. {Refer to processing steps 101 and 102 in FIG. 3} Specifically, the second intermediate device 31 replaces the operation of the channel device 1, drops select out (SLO), responds with service out (SVO), and enters. The output device 2 drops the operational in (OPI) signal and the status in (STI: ##), opens the input / output interface between the input / output device 2 and the second intermediate device 31, and outputs the other input. Prepare for request-in (RQI) from output device 2.

On the other hand, in the channel device 1, the above-mentioned second device is provided between the channel device 1 and the first intermediate device 30 on the side of the channel device 1.
Status in (STI) from intermediate device 31 (##, or
1 and 2, assuming that the request-in (RQI) from the input / output device 2 is received at the time of receiving (DE equivalent), the second intermediate device 31 is regarded as the input / output device 2. I / O interface processing is performed and the status
When (STI) (##, or DE equivalent) is received, the response corresponding to the status of the request-in (RQI), that is, service out (SVO) or service out (SVO) + suppress out ( SPO) is output.

The second intermediate device 31 on the input / output device 2 side
Is the status in (STI) from the above I / O device 2,
In the case of device end (DE) or device end (DE) + modifier (SM), it is considered that there is a possibility of command chain instruction as described above, and service out (instruction from the channel device 1 is issued. SVO) or service out (SVO)
+ Waiting for response by suppress out (SPO). {Refer to processing step 103 in FIG. 3} In the second intermediate device 31, the instruction from the channel device 1 is serviced out.
If only (SVO), it is recognized as a termination instruction without command chain instruction, and select out (SLO), service out
By dropping (SVO), the input / output device 2 drops status in (STI) and operational in (OPI), and opens the input / output interface between the second intermediate device 31 and the input / output device 2. . {Processing steps 104, 105 of FIG.
Also, refer to the operation time chart of FIG. 1} Also, in the second intermediate device 31, the instruction from the channel device 1 is a service out (SVO) for instructing a command chain.
When the response by + suppress out (SPO) is recognized, the service out (SVO) + suppress out (SPO) is sent to the input / output device 2 to instruct the operation of the command chain. {Refer to the processing steps 104 and 106 in FIG. 3 and the operation time chart in FIG. 2} As a result of the operation as described above, as shown in FIGS.
As is clear from the operation time chart of the input / output interface operation between the first intermediate device 30 and the second intermediate device 31, the status input (ST
I) and service out of channel device 1 (SV
O) or service out (SVO) + suppress out (SPO)
If the status in (STI) from the I / O device 2 indicates that there is no possibility of command chain instruction from the channel device 1, the operation in the channel device 1 is not possible. First, I / O device 2
I / O interface processing between the second I / O device and the second intermediate device is terminated, the I / O interface is opened, and the request-in (RQI ) Will be able to deal with.

[0031]

As described above in detail, according to the advanced control method of the standard input / output interface by request-in (RQI) of the input / output device of the present invention, the number of response times of the input / output interface signal is reduced, The performance of the computer system can be improved. In addition, the possibility that the required request-in (RQI) from the I / O device becomes stuck due to the influence of other I / O devices (specifically, the I / O interface is exclusively used) is reduced. There is an effect that the performance of the computer system can be improved.

[Brief description of drawings]

FIG. 1 is an explanatory diagram (1) of the principle of the present invention.

FIG. 2 is an explanatory diagram of the principle of the present invention (No. 2)

FIG. 3 is a flowchart showing an embodiment of the present invention.

FIG. 4 is a diagram (part 1) explaining a long-distance communication means of a conventional input / output interface.

FIG. 5 is a diagram (part 2) explaining a long-distance communication means of a conventional input / output interface.

[Explanation of symbols]

1 Channel device 2 I / O device 30 1st intermediate device 31 2nd intermediate device 100 to 106 Processing step RQI Request in (connection request) SLO Select out OPI Operational in CMO Command out STI Status in (##, DE, DE + SM) SVO service out SPO suppress out (command chain instruction)

Claims (1)

[Claims] 1. A channel device (1) and a plurality of input / output devices (2)
First for long-distance installation of input / output interface for connecting to
In the intermediate device (30) and the second intermediate device (31), the second intermediate device (31) fetches the status of the I / O interface by the connection request (RQI) from the I / O device (2). Is started prior to the operation of the channel device (1), the content of the status is judged by the second intermediate device (31), and the status is device end (DE), or
When device end (DE) + status qualifier (SM), it is determined that the command chain may continue, and when it is any other status, it is determined that the command chain does not continue. In any case, Only the status-in (STI) is transferred to the first intermediate device (30) on the channel device side, and when it is determined in the above judgment that the command chain does not continue, the second intermediate device (31) ) Terminates the preceding interface work and receives the above status in (STI) channel device (1)
And the first intermediate device (30) fetches the status of the input / output interface based on the status in (STI), and the channel device (1) receives the status in (STI).
Service out instruction to (TI) (SVO, or SVO + SPO)
To the second intermediate device (31), and when it is determined in the above determination that the command chain sequence follows the connection request (RQI) sequence,
Based on the service out instruction (SVO, or SVO + SPO) from the channel device (1) between the second intermediate device (31) and the input / output device (2), the input / output interface RQI of input / output device characterized by carrying out work
Control method of standard input / output interface by.