JPH03224051A - Input/output controller - Google Patents

Abstract

PURPOSE:To attain the normal control of the input/output operation of other input/ output devices by polling the presence or absence of a service request, arranging and storing the Nos of input/output devices where the time-out errors are detected for the polling answer at the end of the Nos of other devices, and transmitting the device Nos in accordance with the arrangement of the input/output devices. CONSTITUTION:An input/output controller transmits successively the Nos of plural input/output devices and inquires the presence or absence of a request for transfer of data to perform the transfer of data to the input/output devices based on the answer of the inquiry. A table means 2 of the input/output controller stores the Nos of input/ output devices in the order of their transmission. At the same time, a detection means 3 detects a time-out error of the answer and a store means 4 stores the Nos of input/ output devices where the time-out errors are detected at the end of the Nos of other devices in an array. This array of the device Nos are stored in the means 2. Then a transmission means 5 transmits the device Nos based on the array stored in the means 2. Thus it is possible to inquire the presence or absence of a request for transfer of data to the input/output device having a time-out error at the end of the inquiries given to other input/output devices.

Description

[Detailed Description of the Invention] [Summary] Regarding an input/output control device that polls and inquires about the presence or absence of a service request from an input/output device and exchanges data with the input/output device that has a request, some input/output devices are malfunctioning. The purpose of this system is to provide a polling-based input/output control device that can normally control the input/output operations of other input/output devices even when it cannot respond to polling from an input/output control device due to multiple input/output control devices. An input/output control device that sequentially transmits the machine numbers of the output devices to inquire as to whether there is a request for data exchange, and based on the response, transmits/receives data with the input/output devices, and transmits the machine numbers of the input/output devices. table means for arranging and storing the input/output device according to the order in which the input/output device has detected the timeout error; The device is configured to include means for storing the machine number in the table means and means for transmitting the machine number according to the arrangement of the table means.

[Industrial application field]

The present invention polls input/output devices (referred to as
It relates to an input/output control device (referred to as an IOC) that exchanges data with the computer.

In recent years, GPIB (general interface), a general-purpose interface for digital devices that connects peripheral devices and measuring instruments, has
IOCs that use a polling method that sequentially changes and transmits Ilo device addresses to inquire whether there is a service request, and then perform services such as data transfer when the Ilo responds that there is a request are widely used. There is. If there is an Ilo among the multiple Ilo's connected to such an IOC that cannot respond to polling due to an abnormal state such as power cut or failure, the IOC cannot poll subsequent Ilo's. Otherwise, normal input/output control will not be performed. Therefore, there is a demand for a polling-type IOC that can perform input/output control normally even when Ilo is in an abnormal state.

[Conventional technology]

FIG. 4 is a side view of the configuration of an input/output system in which Ilo and roc are connected via GPIB.

Ilo with data to send to IOC or other Ilo
o outputs a signal SRQ requesting services such as data transfer. When the IOC receives the SRQ signal, it issues a command (SPE) indicating the start of polling, and transmits (polling) the Ilo device address while changing it sequentially. Each polled I10 responds with device state information (status) including the presence or absence of an SRQ signal cause (service request). When the IOC receives a status with a service request, it sends a command SP indicating the end of polling.
The Ilo that was transmitting D and outputting the SRQ signal stops its output and executes data transfer with the IOC or other Ilo.

Here, if there is an abnormal state such as power cut or failure in Ilo,
If there is an Ilo that cannot respond to polling (referred to as a non-response state), a timeout error will occur and the IOC will stop the polling operation, so if a subsequent Ilo is outputting an SRQ signal, the SRQ signal will be You will not be able to receive it. For this reason, in the past, the system had to be stopped until the non-responsive state (10) was recovered, or the engineer had to change the program and
The system was operated with Ilo removed from the polling target, and when the system recovered from a non-responsive state, the engineer changed the program to include Ilo as the polling target.

[Problem to be solved by the invention]

As mentioned above, according to the conventional method, if an Ilo becomes unresponsive due to a failure or other reason, the system must be stopped until the failure is recovered, or the engineer can change the program to remove that Ilo from polling. Since it was removed or installed at the time of restoration, it took a lot of manpower and time, and there was a problem that the system could not function during that time.

The present invention provides a polling-type IOC that can normally control the input/output operations of other ILOs even if some ILOs cannot respond to polling from other ROCs due to a failure or the like.
The purpose is to provide

[Means to solve the problem]

FIG. 1 shows a block diagram of the principle of the present invention.

In the figure, 2 is a table means for arranging and storing the machine numbers of input/output devices in accordance with the order of transmission, 3 is a means for detecting a timeout error in response to an inquiry as to whether there is a request for data exchange, and 4 is a means for detecting a timeout error. means for arranging the machine numbers of the input/output devices that have been inputted at the end of the machine numbers of other devices and storing them in the table means 2; and 5 means for transmitting the machine numbers according to the arrangement of the table means 2.

[Operation] According to the present invention, the input/output control device sequentially transmits the machine numbers of a plurality of input/output devices to inquire as to whether there is a request for data exchange, and transmits/receives data with the input/output devices based on the response. In the table means 2, the machine numbers of the input/output devices are arranged and stored in accordance with the order of transmission, the detection means 3 detects a response timeout error, and the storage means 4 stores the machine numbers of the input/output devices in which the timeout error has been detected. The machine number is arranged at the end of the machine numbers of other devices and stored in the table means 2, and the transmitting means 5 transmits the machine number according to the arrangement of the table means 2, so that data can be exchanged with the input/output device in which the timeout error has been detected. It becomes possible to make an inquiry about the presence or absence of a request at the end of an inquiry to other input/output devices.

[Example] Hereinafter, an example of the present invention will be described with reference to FIGS. 2 and 3. The same reference numerals indicate the same objects throughout the figures. Components in FIG. 2 that correspond to those in FIG. 1 are surrounded by dashed lines.

In the block diagram of the embodiment of the present invention shown in FIG. 2, the interface section 9a has a C
Controls signal exchange based on the PIB interface.

The control unit 8a causes a processor (not shown) to execute a program stored in a memory (not shown) to control each unit and perform the functions of the l0C 20 according to the present invention.

That is, when a signal SRQ requesting a service such as data transfer is received from Ilo, a command SPE indicating the start of polling is sent to the GPIB, and the polling unit 5
Instruct the interface unit 9a to start polling, and send the status of the response from Ilo to the polling to the interface unit 9a.
Receive via. When the status includes a service request that causes SRQ signal transmission, services such as data transfer are performed with the Ilo, and when there is no service request, the polling section 5a is instructed to proceed with polling to the next Ilo.

Table 2a is a memory in which Ilo device addresses are arranged in polling order.

The polling unit 5a starts polling in accordance with the instructions from the control unit 8a, and refers to the table 2a to proceed with polling in the order in which the device addresses are arranged.

The detection unit 3a receives a polling start command S from the control unit 8a.
A timer (not shown) monitors the time from when the PE is sent to when the status is responded to, and if no response is received within a certain period of time, it is detected as a timeout error.

The storage unit 4a arranges the Ilo device address where the timeout error was detected by the detection unit 3a at the end of the other I10 addresses in the table 2a.

The operation of the embodiment of the present invention will be explained with reference to the flowchart of FIG. Here, l1011.
Assume that polling types are arranged in the order of 12.13.14. It is also assumed that l1012 is in a non-responsive state due to a failure or the like.

■For example, l1013 transmits an SRQ signal.

(2) Upon receiving the SRQ signal, the control unit 8a issues a polling start command SPE and instructs the polling unit 5a to start polling.

■When polling reaches l1012 via l1011, since l1012 cannot respond with the status, the detection unit 3a detects a timeout error, and ■The storage unit 4a stores the device address in table 2a in l101.
Change the arrangement to 1.13.14.12.

■For example, requests for l1013 cannot be accepted, so
Send the SRQ signal again or again.

(2) Similarly to (2) above, when polling reaches l1013 via 11011, l1013 responds with a status indicating a service request.

(2) The control unit 8a sends a polling end command SPD to stop polling, and provides services such as data transfer to l1013.

■Hereafter, in the same procedure as above ■, ■, and ■, l0C20
, l1011.13 and 14, input/output operations are successfully performed without timeout errors for polling.

■When l1012 recovers and sends an SRQ signal, polling is performed via l1011.13 and l1014.
2, the l1012 normally performs input/output operations in the same manner as in steps (1), (2), and (3) above, and the l1012 automatically returns to the system.

Therefore, based on the detection by the detection unit 3a, the storage unit 4a rearranges the device address of Ilo in the non-responsive state to the end of the array in the table 2a, and the polling unit 5a changes the arrangement of the device addresses in the table 2a. The configuration is such that polling is performed in accordance with the polling method to prevent the polling operation from being interrupted midway.

In this embodiment, an example is shown in which there is only one Ilo in the non-responsive state, but even if there are a plurality of Ilo's, the same operation and effect can be achieved.

〔Effect of the invention〕

As explained above, according to the present invention, an IOC that controls Ilo using a polling method detects an Ilo that has become unresponsive due to a failure or the like, and arranges the device address at the end of the table. Since polling is performed according to the order, the polling operation for normal Ilo will not be stopped midway due to no response, so normal input/output operations can be executed by effectively disconnecting the non-responsive Ilo from the system. In addition, when Ilo is restored, it can be automatically returned to the system. Therefore, there is an effect that a system with high reliability can be constructed without stopping the system due to a failure of Ilo or the like.

[Brief Description of the Drawings] Fig. 1 is a principle block diagram of the present invention, Fig. 2 is a block diagram showing an embodiment of the present invention, Fig. 3 is a flowchart of the embodiment of the present invention, and Fig. 4 is an input/output diagram. It is a side view of the system configuration. In the figure, 2 is a table means, 2a is a table, 3 is a detection means, 3a is a detection section, 4 is a storage means, 4a is a storage section, 5 is a transmission means, 5a is a polling section, 8a is a control section , 9a is an interface section, ratio 12.13.14 is an input/output device (Ilo), and 20 is an input/output control device (IOC). A block diagram of the principles of the present invention. Fig. 1. A side view of the configuration of the input/output system. Fig. 4. A block diagram showing an embodiment of the present invention. Fig. 2. A flow chart of an embodiment of the present invention.

Claims (1)

[Scope of Claims] An input/output control device that sequentially transmits the machine numbers of a plurality of input/output devices to inquire as to whether there is a request for data exchange, and transmits/receives data with the input/output devices based on the response. , table means (2) for arranging and storing machine numbers of input/output devices according to the order of transmission; means (3) for detecting a timeout error in the response; and a machine number of the input/output device in which the timeout error has been detected. The table means (2) is arranged at the end of the machine numbers of other devices.
); and means (5) for transmitting the machine number according to the arrangement of the table means (2).