JP2778995B2 - Channel processing method - Google Patents

Description

Detailed Description of the Invention [Table of Contents] Overview Industrial application field Conventional technology Problems to be solved by the invention Means to solve the problem Actions Embodiment I. Correspondence between the embodiment and FIG. 1 II. Configuration of the embodiment III. Operation of the embodiment IV. Summary of the embodiment V. Modifications of the invention Effects of the invention [Overview] In a computer system, a channel configured to connect an external input / output device via an optical transmission line Regarding the processing method, a relay device having an error occurrence notifying means via a transmission line and an input / output control device are connected to a channel device connected to the channel control device for the purpose of reducing the load on the central processing unit. In a channel processing method for inputting or outputting data through a system including a device to an input / output control device, an error of the channel device is executed during execution of an instruction for inputting or outputting the data. When the information requesting unit receives a notification of the occurrence of the error from the error occurrence notifying unit of the relay device, the error information requesting unit sends a command of an error detailed information transmission request to the error information sending unit of the relay device, When the error information sending means of the relay device receives the command of the error detailed information transmission request, sends back a command including the error detailed information from the error information sending means to the channel device,
When the detailed information notifying means of the channel device receives the command including the detailed information of the error, the detailed information notifying means holds at least the detailed information of the command and notifies the channel control device of the reception of the detailed information. The channel control device that has received the notification of the reception of the detailed information issues a termination interrupt of the instruction being executed to the higher-level device of the channel control device.

[Industrial applications]

The present invention relates to a channel processing system for connecting an external input / output device via an optical transmission line in a computer system.

[Conventional technology]

FIG. 8A shows the configuration of the computer system. This computer system includes a central processing unit (CPU) 511, a main storage unit (MSU) 513, a storage control unit (MCU) 515, a channel control unit (CHP) 517, and a plurality of channel units (CH) 519. And a plurality of input / output control devices (IOCs) 521, 523, 525,... Connected to each channel device 519.
And a disk device 531, a magnetic tape device 533, and a display terminal 535 connected to each input / output control device.

When the computer main body 510 transmits and receives data to and from an input / output device such as the disk device 531, the central processing unit 511 in the computer main body 510 includes an input / output device corresponding to the channel controller 517, the channel device 519, and the target input / output device. Instructions and data are transmitted and received via the output control device.

By the way, recently, with the progress of high-speed and large-capacity optical transmission technology, it is possible to give flexibility to the system configuration by replacing a transmission line in a computer system with an optical transmission line. .

For example, FIG. 8B shows a configuration of a computer system in which the connection between the computer main body 510 and the input / output device is made via an optical transmission line. This computer system includes a computer main body 510 shown in FIG. 9A, two communication devices 611 and 613 for mutually converting between a serial optical signal and a parallel electric signal,
An input / output control device 521 and the like are provided. The channel device 519 in the computer main body 510 is connected to a communication device 611. The communication device 611 is connected to an input / output control device 521 via an optical transmission line and a communication device 613.

The input / output control devices 523 and 525, the disk device 531, the magnetic tape device 533, and the display terminal 53 shown in FIG.
5 are also connected, and illustration in FIG. 8B is omitted.

As described above, by connecting the input / output device such as the disk device 531 via the optical transmission path, there is an advantage that the input / output device can be installed at an arbitrary place. For example, in the computer system of FIG. 8A, the computer main body 510 and the input / output control device 521
It was necessary to connect between the main unit 510 and the input / output control unit 521 by a parallel signal line of about 100 m at the maximum, but in the computer system of FIG. It becomes possible to connect with an optical fiber (serial optical transmission line). Therefore, when considering a factory or a laboratory, the computer main body 510 and the input / output devices can be dispersedly arranged at an arbitrary place on the site, and the system configuration can be made flexible.

[Problems to be solved by the invention]

When the channel device 519 is directly connected to the input / output control device 521 or the like as shown in FIG. 8 (a), the input / output control device 521 or the like responds to an input / output command (I / O command) from the channel device 519. Works for Accordingly, the channel device 519 can collect information as to the sequence in which the error occurred between the input / output control device 521 and the like or the detailed status of the interface at that time as log information, and find the cause of the failure. Can be.

However, as shown in FIG.
When the 9 and the input / output device 521 are connected via the communication devices 611 and 613, the channel device 519 indirectly executes the I / O command via the communication devices 611 and 613. Therefore, in such a connection form, when an error occurs during execution of an I / O instruction, the communication device 6
It is necessary to find out the cause of the failure by distinguishing between an error on a conventional interface connecting the I / O controller 13 and the input / output control device 521 or the like, or an error on the interface via an optical transmission line.

By the way, in the case of an error that has occurred on the optical transmission path,
Since the channel device 519 controls the communication device 611, detailed information on the error can be collected. However, if an error occurs on the conventional interface connecting the communication device 613 and the input / output control device 521, the communication device 613
Is monitoring this interface, so no details of the error are available. Therefore, after the occurrence of this error is notified as a status to the channel device 519, the operating system (OS) of the computer main body 510
Issue a new I / O instruction such as a sense (SENSE) command to collect detailed error information, and there is a problem that the load on the central processing unit 511 is large.

The present invention has been made in view of such a point, and an object of the present invention is to provide a channel processing method which reduces a load on a central processing unit.

[Means for solving the problem]

FIG. 1 is a block diagram showing the principle of the channel processing system according to the first and second aspects of the present invention.

In the figure, an error is detected from information received by the input / output control device 121 during execution of a command connected to the channel control device 109 and a command for inputting or outputting data connected to the input / output control device 121. When it is detected that an error has occurred, a command to the effect that an error has occurred is sent to the channel device. A relay device 131 having an error occurrence notifying means 141 is connected via a transmission line to input or output data. In the channel control method that is performed,
The error information requesting unit 151 transmits detailed error information to the relay device 131 when receiving a command indicating that an error has occurred from the error occurrence notifying unit 141 via the transmission path in the channel device 111. Send request command.

The error information sending means 161 is provided in the relay device 131, and, when receiving a command of a detailed information transmission request of the error via the transmission line from the error information requesting means 151, a command including the detailed information of the error. Wrap.

The detailed information notifying means 171 is provided in the channel device 111 and, when receiving a command including the detailed information of the error from the error information transmitting means 161 via the transmission line, at least the detailed information of the command And notifies the channel control device 109 of the reception of the detailed information in response to the reception of the command.

Then, the channel control device 109, which has received the notification of the reception of the detailed information, causes the host device of the channel control device 109 to issue a termination interrupt of the instruction being executed,
The invention according to claim 1 is configured.

According to a second aspect of the present invention, in the channel processing system according to the first aspect, the relay device 111 is a channel adapter, and the transmission path is a serial transmission path connecting the channel device and the channel adapter.

[Action]

Under the control of the channel control device 109 to which the control relating to the command issued from the higher-level device is passed, the higher-level device receives data via a channel device connected to the channel control device 109, or communicates with a device for output. While performing input or output according to the issued command between the relay device
When the error information requesting unit 151 of the channel device 151 receives the notification of the occurrence of the error from the error occurrence notifying unit 161 of the channel 131, the error information requesting unit 151 sends an error notification to the error information transmitting unit 161 of the relay device 131. Sends a detailed information transmission request command.

When the error information sending unit 161 of the relay device 131 receives the command of the error detailed information transmission request, the error information sending unit 161 sends a command including the error detailed information to the detailed information notifying unit 171 of the channel device 111. Send it back.

When the detailed information notifying unit 171 of the channel device 111 receives the command including the detailed information of the error, the detailed information notifying unit 171 holds at least the detailed information of the command and sends the detailed information to the channel control device 109. Notify of reception. The channel control device 109, which has been notified of the reception of the detailed information, interrupts the host device of the channel control device 109 by terminating the instruction being executed.

Thus, in the sequence of issued instructions,
Since detailed information of an error that has occurred in a processing system lower than the channel device 111 during execution of the instruction can be collected up to the channel device 111, as in the related art, the channel device 111
It is not necessary to newly issue an instruction for collecting detailed information of an error that has occurred in a lower processing system, which can contribute to a reduction in the load on a higher-level device.

〔Example〕

Hereinafter, embodiments of the invention described in claims 1 and 2 will be described in detail with reference to the drawings.

FIG. 2 shows a configuration of a computer system according to one embodiment of the present invention. FIG. 3 shows a detailed configuration of an optical channel device according to one embodiment, and FIG. 4 shows a detailed configuration of an optical channel adapter according to one embodiment.

I. Correspondence Between Embodiments and FIG. 1 Here, correspondences between the embodiments of the first and second aspects of the present invention and FIG. 1 will be described.

 The channel device 111 corresponds to the optical channel device 219.

The input / output control device 121 corresponds to the input / output control devices 221, 223, and 225.

The relay device 131 corresponds to the optical channel adapters 241, 243, 245.

The error notification unit 141 includes a microprocessor 411,
It corresponds to the microprocessor interface 413 and the data pattern creation unit 421.

The error information requesting unit 151 includes a microprocessor 311,
It corresponds to the microprocessor interface 313 and the data pattern creation unit 321.

The error information sending means 161 includes a microprocessor 411,
It corresponds to the microprocessor interface 413, the data pattern creation unit 421, the data transfer handler 441, and the I / O interface control unit 443.

Assuming that the above-mentioned correspondence exists, an embodiment of the present invention will be described below.

II. Configuration of Embodiment In FIG. 2, the computer system of the embodiment includes a central processing unit (CPU) 211, a main storage unit (MSU) 213, a storage control unit (MCU) 215, a channel control unit (CHP) 217, Multiple Optical Channel Equipment (OCH) 219 and Service Processor (SVP) 251
, A plurality of optical channel adapters (OCHA) 241, 243, and 245 connected to each optical channel device 219 via an optical transmission line, and a plurality of input / output control devices (IOCs) corresponding to each optical channel adapter 221, 223, and 225, and a disk device 231, a magnetic tape device 233, and a display terminal 235 connected to each input / output control device.

The central processing unit 211 in the computer main body 210 includes a channel control device 217, an optical channel device 219, and optical channel adapters 241-2.
I / O controller corresponding to 45 and target I / O device
Data transmission / reception is performed via 221 to 225.

In addition, the detailed configuration of the optical channel
Shown in the figure.

In FIG. 3, an optical channel device 219 includes a microprocessor 311, a microprocessor interface 313, a data pattern creating unit 321, a parallel-serial conversion circuit (P / S circuit) 323, and an electro-optical conversion circuit (E / O circuit). 325, light-
It includes an electrical conversion circuit (O / E circuit) 331, a serial-parallel conversion circuit (S / P circuit) 333, a data pattern analysis unit 335, and a data transfer handler 351.

The microprocessor 311 controls the overall operation of the optical channel device 219, and is controlled by an external channel control device 21.
7 and the service processor 251.

The microprocessor interface 313 is for exchanging data and instructions between the microprocessor 311 and each component of the optical channel device 219. The microprocessor interface 313 is connected to a microprocessor 311, a data transfer handler 351, a data pattern creation unit 321, and a data pattern analysis unit 335.

The O / E circuit 331 converts the optical signal input via the optical transmission line into an electric signal (serial data), and the electric signal is then converted into parallel data by the S / P circuit 333. Further, the pattern analysis is performed by the data pattern analysis unit 335 based on the parallel data, and the command, data, and the like transmitted via the optical transmission path are identified. The identified command and the dummy command are input to the microprocessor interface 313, and the data (read data sent from each input / output device) is input to the data transfer handler 351.

On the other hand, the data pattern creation unit 321 converts the command output from the microprocessor interface 313 into data (write data for each input / output device) output from the data transfer handler 351 or dummy data output from the microprocessor interface 313. In addition, a pattern is created, and parallel data including the created pattern is input to the P / S circuit 323. The P / S circuit 323 converts the parallel data into serial data (electric signal), and the E / O circuit 325 converts the electric signal into an optical signal and sends it to the optical transmission line.

The data transfer handler 351 is for transmitting and receiving data between the optical channel device 219 and the main storage device 213. Data output from the data transfer handler 351 is stored in the main storage device 213 via the storage control device 215. Conversely, data read from the main storage device 213 is data transferred via the storage control device 215. Handler 351
Is input to

FIG. 4 shows the detailed configuration of the optical channel adapter 241 (the optical channel adapters 243 and 245 have the same configuration).

In FIG. 4, an optical channel adapter 241 includes a microprocessor 411 and a microprocessor interface 41.
3, Data pattern creation unit 421, P / S circuit 423, E / O circuit 425, O /
An E circuit 431, an S / P circuit 433, a data pattern analysis unit 435, a data transfer handler 441, and an I / O interface control unit 443 are provided.

The microprocessor 411 controls the overall operation of the optical channel adapter 241. Data and instructions are exchanged with other components via the microprocessor interface 413.

The microprocessor interface 413 is connected to the microprocessor 411, the data pattern creation unit 421, the data pattern analysis unit 435, the data transfer handler 441, and the I / O interface control unit 443.

The O / E circuit 431 converts the optical signal input from the optical channel device 219 via the optical transmission line into an electric signal (serial data).
The electrical signal is then converted to parallel data by the S / P circuit 433. Further, the pattern analysis is performed by the data pattern analysis unit 435 based on the parallel data, and the command and the dummy command transmitted via the optical transmission line are transmitted to the microprocessor interface 413 as data (write to each input / output device). ) Is input to the data transfer handler 441.

On the other hand, the data pattern creation unit 421 adds a command output from the microprocessor interface 413 or a dummy command to data output from the data transfer handler 441 (read data read from each input / output device) to create a pattern. That is, the parallel data including the created pattern is input to the P / S circuit 423. The P / S circuit 423 converts the parallel data into serial data, and the E / O circuit 425 converts the electric signal into an optical signal and sends it to an optical transmission line.

Data transfer handler 441 is an optical channel adapter 241
It transmits and receives data between the input / output control device 221 and the like, and is connected to the input / output control device 221 and the like via a directional bus line.

The I / O interface control unit 443 is for transmitting and receiving control signals between the optical channel adapter 214 and the input / output control device 221 and the like, and has a tag line having directionality with the input / output control device 221 and the like. Connected through.

III. Operation of Embodiment Next, the operation of the above-described first and second aspects of the invention when an error occurs during data input / output will be described.

FIG. 5 shows a sequence when an error occurs during execution of an I / O instruction. As an error, for example, an error occurring in the parity of the status sent from the input / output control device 221 to the optical channel adapter 241 is considered.

First, from the optical channel device 219 to the optical channel adapter 2
A CNCT (start request) command is sent to 41. The microprocessor 311 of the optical channel device 219 sends a CNCT command to the data pattern creation unit 321 via the microprocessor interface 313. Data pattern creation unit 3
21 creates a predetermined pattern corresponding to this command. The created pattern is transmitted to the optical transmission line via the P / S circuit 323 and the E / O circuit 325, and is transmitted to the optical channel adapter 241.

When the optical channel adapter 241 receives the CNCT command sent from the optical channel device 219, the disk device
The selection for the input / output control device 221 to which the 231 is connected is started.

The microprocessor 411 of the optical channel adapter 241 is
The I / O interface control unit 443 is controlled via the microprocessor interface 413 to address out (ADD)
RESS OUT signal and SELECT OUT signal are sent to the tag line. Also, an operation-in (OPERATIONAL IN) signal and an address-in (ADDRESS I) sent back from the input / output control device 221 via the tag line.
N) Monitor the signal.

Further, the microprocessor 411 sends a command-out (COMMAND OUT) signal to the tag line, and simultaneously controls the data transfer handler 441 to send a predetermined command corresponding to the I / O instruction to the bus line. .

Next, in response to the command-out signal and the command, the input / output control device 221 sends a status-in (STATUS IN) signal to the tag line and a status to the bus line. The status-in signal is sent to the I / O interface controller 4
Received at 43, status is transferred to data transfer handler 441
Received at.

By the way, the data transfer handler 441 monitors the parity of the received status, and detects a parity error if the status parity is abnormal. The occurrence of this parity error is notified to the microprocessor 411, and the microprocessor 411 responds to this notification by sending an IER command for transmitting the error occurrence to the optical channel device 2.
Send to 19. A pattern corresponding to the IER command is created by the data pattern creation unit 421, and the P / S circuit 423 and the E / O circuit 425
From the optical transmission line.

At this time, the optical channel adapter 241 stores an error code and various information at the time of occurrence of an error regarding the tag line and the bus line. For example, information about tag lines is I / O
The information on the bus line is stored in a register (not shown) in the data transfer handler 441, and stored in a register (not shown) in the interface control unit 443.

Next, when receiving the IER command, the optical channel device 219 sends an SLRST (reset instruction) command to the optical channel adapter 241.

Upon receiving the SLRST command, the optical channel adapter 241 ends a series of selection operations performed on the input / output control device 221 and then RSTCMP (reset end)
The command is sent to the optical channel device 219.

Next, the optical channel device 219 is
Sends an ERQ (log request) command to send detailed information about the error.

Upon receiving the ERQ command, the optical channel adapter 241 reports various information related to the error stored at the time of occurrence of the error by using a SELG (log transmission) command. The details of the transmission and reception of the error information will be described later.

After receiving the error information reported by the SELG command, the optical channel device 219 generates a termination interrupt to the central processing unit 211. Further, a log collection request is issued to the service processor 251 in parallel with this interrupt operation. The service processor 251 collects the error information captured in the optical channel device 219 in response to the log collection request, and executes processing such as error analysis.

FIG. 6 shows the details of the ERQ command and the SELG command described above.

For example, the ERQ command includes an ERQ0 command, an ERQ1 command, and an ERQ2 command, each of which has a predetermined bit configuration as shown in FIG. 6 (a). In addition, the SELG command includes the SELG command corresponding to each of the ERQ0 commands, etc.
There are a 0 command, a SELG1 command, and a SELG2 command, each of which has the bit configuration shown in FIG. 6 (b). SE
Each of the LG0 commands and the like contains different error information, and is transmitted and received as necessary.

In FIG. 6B, “ERROR CODE” indicates an error code, “EDR” indicates data set in an error detection register (not shown) in the optical channel adapter 241 (details will be described later), and “TAG IN” indicates Tag line at the time of error (input side)
“TAG OUT” indicates the bit status of the tag line (output side) when an error occurs, “BUS IN” indicates the bit status of the bus line (input side) when an error occurs, and “BUS OUT” indicates The bit status of the bus line (output side) at the time of occurrence of an error is shown.

Therefore, when only the error code and the contents of the error detection register are required for error analysis, the optical channel device 219 sends out only the ERQ0 command, and the optical channel adapter 241 sends back only the corresponding SELG0 command. Also,
If all information is needed, first, ERQ0 command, S
It sends and receives an ELG0 command, then sends and receives an ERQ1 command and a SELG1 command, and then sends and receives an ERQ2 command and a SELG2 command.

FIG. 7 shows details of various types of information included in the SELG command.

FIG. 11A shows the contents of “EDR” in the SELG0 command. “DSCI” is a bit for disconnect-in corresponding to an error of the input / output control device 221, “INVTG” is a bit for invalid tag-in corresponding to an error in the protocol, and “BIPE” is an input / output The bit for the bus-in parity error corresponding to the parity error on the bus to which the control device 221 is connected, and the “RINGC” is the bit for the ring check corresponding to the case where the data valid time on the bus is short. Each is shown. Other bits are “0”
Alternatively, although it is fixed data of "1", if other error information is to be added, it is assigned to these bits.

FIG. 2B shows the contents of “TAG IN” in the SELG1 command. "RQI" stands for Request In
N), the bit corresponding to the status in (STATUS IN), the bit corresponding to the service in (SERVICE IN), the data corresponding to the data in (DTI). The bit corresponding to “DATA IN” is “OPI”
Is the bit corresponding to Operational In (OPERATIONAL IN), and "ADI" is Address In (ADDRESS IN)
"MKI" is the mark in (MARK I
N), the bit corresponding to “SLI” is select-in (SE
LECT IN).

FIG. 3C shows the contents of “BUS IN” in the SELG1 command. Each of “BI0 to BI7” is an input / output control device 221
2 shows each bit of the bus line on the side (upward side) to which data is input.

FIG. 11D shows the contents of “TAG OUT” in the SELG2 command. "OPO" is Operational Out
AL OUT), “CMO” is the bit corresponding to Command Out (COMMAND OUT), “SLO” is the bit corresponding to Select Out (SELECT OUT),
“SPO” indicates the bit corresponding to the SUPPRESS OUT, and “ADO” indicates the address out (ADDRESS OU).
T) bit corresponding to "SVO", bit corresponding to service out (SERVICE OUT), "DTO" bit corresponding to data out (DATA OUT), "MTO" metering out Bits corresponding to (METERING OUT) are shown.

FIG. 11E shows the contents of “BUS OUT” in the SELG2 command. Each of “BO0 to BO7” is an input / output control device 221.
2 shows each bit of the bus line on the side where data is output (downward side).

IV.Summary of Embodiment As described above, when an error occurs on the interface between the optical channel adapter 241 and the input / output control device 221, the disk device 231 during the execution of the I / O instruction by the optical channel device 219, first, The optical channel adapter 241 is an optical channel device 2
Sends an IER command to notify error occurrence to 19. Next, after terminating the selection operation by the optical channel adapter 241, an ERQ command for requesting error information is output from the optical channel device 219 and a SELG command including detailed error information is returned from the optical channel adapter 241. I do. Thereafter, an interrupt is generated in the central processing unit 211, and processing such as analysis by a program is executed.

Therefore, the central processing unit 211 does not need to collect the detailed information of the error by executing the program.
The load of 211 is reduced.

V. Modifications of the Invention In the above-described embodiments of the first and second aspects of the invention, a computer system via an optical transmission line is considered. For example, RS-232C
The inventions of claims 1 and 2 can also be applied to a case where connection is made via an interface.

Further, in this embodiment, a case is considered in which detailed information of an error related to a parity error generated between the optical channel adapter 241 and the input / output control device 221 is collected. The same applies to a case where the optical channel adapter 241 detects another error, such as when an error occurs.

Further, in "I. Correspondence between the embodiment and FIG. 1",
The correspondence between the inventions described in claims 1 and 2 and the embodiments has been described. However, the present invention is not limited to this, and various modifications may be made to the inventions described in claims 1 and 2. Something can be easily deduced by those skilled in the art.

〔The invention's effect〕

As described above, according to the present invention, when an error occurs in a processing system lower than a channel device during a sequence of instructions issued by a higher-level device, notification of the occurrence of the error and request and transmission of detailed information of the error are performed. Can be collected by a higher-order accelerator means up to a channel device that can be accessed without using a new command in the sequence of issued commands, so that an operation system for collecting detailed information of errors, etc. This eliminates the need to start a new execution of the program, greatly contributing to a reduction in the load on the host device.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the principle of the channel processing system according to the present invention, FIG. 2 is an overall configuration diagram of one embodiment of the present invention, FIG. 3 is a configuration diagram of an optical channel device of one embodiment, and FIG. FIG. 5 is a diagram for explaining the operation of one embodiment, FIG. 6 is a diagram for explaining commands in one embodiment, FIG. 7 is a diagram for explaining error information in one embodiment, FIG. FIG. 8 is an explanatory diagram of a conventional example. In the figure, 111 is a channel device, 121 is an input / output control device, 131 is a relay device, 141 is an error occurrence notifying means, 151 is an error information requesting means, 161 is an error information sending means, 210 is a computer main body, 21
1 is a central processing unit (CPU), 213 is a main storage unit (MSU), 21
5 is a storage controller (MCU), 217 is a channel controller (CH
P), 219 is an optical channel device (OCH), 221,223,225 is an input / output control device (IOC), 231 is a disk device, 233 is a magnetic tape device, 235 is a display terminal, 241,243,245 is an optical channel adapter (OCHA), and 251 is a service Processor (S
VP, 311,411 are microprocessors, 313,413 are microprocessor interfaces, 321 and 421 are data pattern creation units, 323 and 423 are parallel-serial conversion circuits (P / S
Circuits), 325, 425 are electro-optical conversion circuits (E / O circuits), 331,
431 is an optical-electrical conversion circuit (O / E circuit), 333,433 is a serial-parallel conversion circuit (S / P circuit), 335,435 is a data pattern analysis unit, 351,441 is a data transfer handler, and 443 is
It is an I / O interface control unit.

Claims (2)

(57) [Claims] An error is generated from information received by the input / output control device during execution of a channel device connected to the channel control device and an instruction for inputting or outputting data which is connected to the input / output control device. A channel which is connected to a relay device having an error occurrence notifying means for sending a command to the effect that an error has occurred to the channel device via a transmission line, and performs data input or output. In the processing method, when a command indicating that an error has occurred in the channel device via the transmission path from the error occurrence notifying unit is received from the error occurrence notifying unit, an error transmission command for a detailed information transmission request of the error is sent to the relay device. An information requesting means, and a command for requesting transmission of detailed error information from the error information requesting means via the transmission path in the relay device. An error information sending unit that returns a command containing the detailed information of the error when received; and a command in the channel device, the command including the detailed information of the error being received from the error information sending unit via the transmission path. The detailed information notifying means for holding at least the detailed information of the command and notifying the channel control device of the reception of the detailed information in response to the reception of the command. Wherein the channel control device that has received the command is configured to interrupt the end of the instruction being executed to a higher-level device of the channel control device. 2. The channel processing system according to claim 1, wherein said relay device is a channel adapter, and said transmission line is a serial transmission line connecting said channel device and said channel adapter. method.