JPH0219498B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical Field of the Invention] The present invention provides a method for remote stations.
The present invention relates to an input/output control method that transmits not only commands and data but also flags and data lengths present in channel command words. [Prior art and problems] In the conventional technology, in order to start a remote station connected via a line, a command code or a command code and data (order, write data, etc.) must be sent as text. It was on. This conventional method has the following drawbacks. (b) Since this is different from the control method for peripheral devices connected through a tag bus type channel interface, a special program must be created to control devices at remote stations. (b) Since the number of bytes of read data cannot be specified for a remote station, it is difficult to perform general control over input/output devices. (c) Since multiple commands cannot be sent to remote stations simultaneously, it is difficult to improve processing speed. [Object of the Invention] It is an object of the present invention to eliminate the above-mentioned drawbacks. It is an object of the present invention to provide an input/output control method having the characteristics of being able to use a normal input/output device as a station device and efficiently transferring data from a main body system to a remote station. [Structure of the Invention] Therefore, the input/output control method of the present invention includes: a central processing unit; a remote station channel connected to the central processing unit; and a communication control device and a modem connected to the remote station channel. In an information processing system that includes a connected circuit and a remote station connected to the line, the remote station channel includes an input/output interface control section, a line control section, and a subchannel area corresponding to each device. , an input/output command queue table having an entry in which a device address and a registration flag are written, and a transmission buffer. To,
the next channel address word, the command code in the channel control word corresponding to the relevant input/output instruction,
Writes the data address in the channel control word, the control flag in the channel control word, and the byte count in the channel control word, and also writes the address and address of the device in the entry of the input/output instruction queue table. The line control unit is configured to write a registration flag indicating new registration, and the line control unit refers to the input/output command queue table, fetches a device address with a registration flag indicating new registration, and performs selection based on the device address. When a message is created and sent on the line, and an acknowledgment is received, the command code, control flag, and byte count stored in the subchannel area corresponding to the device address are written to the transmission buffer, and the write system In the case of command or control commands, write data or control
The data is also stored in the transmission buffer, and if the control flag indicates a command chain, check whether the next command can be sent with the same command text, and if possible, send the next channel control word. Writes the command code, control flag, and byte count to the transmit buffer, writes write data or control data to the transmit buffer as necessary, and sends the contents of the transmit buffer onto the line as the same command text. It is characterized by being configured. [Embodiments of the Invention] The present invention will be described below with reference to the drawings. In FIG. 1, 1 is a communication control device, 2 is a modem, 3 is a communication line, 4 is a remote station channel, 5 is a remote station processor, 6 is a display, 7 is a printer, and 8 is a remote station processor.
respectively indicate a floppy disk device. The processing program and management program are executed by the central processing unit. The remote station channel 4 executes a channel control program consisting of an input/output interface section and a line control section. Channel 4 is connected to communication line 3 via communication control device 1 and modem 2 .
The remote station is composed of a modem 2, a communication control device 1, a processor 5, a display 6, a printer 7, and a floppy disk device 8. Processor 5 executes a remote station control program consisting of a line control section and a device control section. FIG. 2 is a diagram showing the data flow in the control area. In Figure 2, CAW is the channel address word, CCW is the channel command word, DCB is the device status byte, CSB is the channel status byte, CC is the command code, ADR is the data address, and F is the flag. ,
CNT is byte count, SIO is start I/
O and BF indicate buffers, respectively. The soft control area of the main memory of the main body system includes an area that holds channel addresses and device addresses, an area that holds DSB/CSB, CNT, and Next CAW, a CAW holding area, a CCW area, and a data area 1. There is also a data area 2, etc. The CCW area stores CCW columns. The channel control program area resides in the memory of the remote station channel,
This control area includes a plurality of subchannel areas, an asynchronous interrupt table, an SIO queue table, a ball queue table, a transmit buffer, a receive buffer, a poll buffer, and the like. In the subchannel area, DSB/CSB, Next CAW,
CC, ADR, F, CNT, sense byte, etc. are stored. The asynchronous interrupt table has an entry to record the number of registrations and a device address.
It has multiple entries for writing DSB/CSB. The SIO queue table has an entry for writing the number of SIO registrations and a plurality of entries for writing device addresses and registration flags. FIG. 3 explains the registration flags of the SIO queue table, where bit 5 shows the CCW execution end flag, bit 6 shows the CCW transfer in progress flag, and bit 7 shows the new registration flag. CCW
The execution end flag is turned on when CCW execution has finished, the CCW transfer flag is turned on when transferring the CCW to a remote station, and the new registration flag is turned on when registering a device address in the SIO queue. Ru. paul kiyu
The table has multiple entries: one entry for the poll watch timer, one entry for the poll queue pointer, and one entry for the station address. The communication control device is provided with a timer, a transmission register, a reception register, and the like. According to the invention, the CCW and its associated data are sent to a remote station. Note that communication between the main system device and the remote station is performed by a polling/selecting procedure. FIG. 4 is a diagram explaining the selecting sequence. FIG. 4A is a diagram showing the selecting sequence in the case of CCW, write, or control system. The main system device sends a selecting signal (telegram) Sel-SQ, and when an acknowledgment ACK ₀ is returned, it sends a command text. Upon receiving this and successfully executing the command, the remote station returns an acknowledgment ACK ₁ and the main system sends an EOT. When the CCW is write, the command text consists of a write command and write data, and when the CCW is control, the command text consists of a control command and control data. Fourth
Figure B is a diagram showing the selecting sequence when CCW is a read-related command. The main body system sends a selecting signal Sel-SQ, and when an acknowledgment ACK ₀ is returned, it sends a command text consisting only of a read command. Upon receiving this command text, the remote station executes it and sends the read data text, and upon receiving the read data text, the main body sends an acknowledgment ACK ₁ and acknowledges the
Upon receiving ACK ₁ , the remote station
Send EOT. FIG. 4C is a diagram showing a selecting sequence when a write or control type command is chained to the next command. In this case, the affirmative response in Figure 4 A
Send ACK ₁ followed by Next command text. FIG. 4D shows a sequence in which the next command is chained to a read-related command. In this case, after the sequence shown in FIG. 4B, the selecting signal is sent again, and after an acknowledgment ACK ₀ is sent, the Next command text is sent. FIG. 4E is a diagram showing a selecting sequence when a command cannot be executed normally at a remote station. In this case,
The remote station returns an EOT after receiving the command text. Note that in this case, the end status can be captured by a polling sequence. FIG. 5 is a diagram explaining the polling sequence. FIG. 5A is a diagram showing a polling sequence when no poll data exists at all. The main system device is a polling signal (telegram) Poll−
Send the SQ to the first remote station,
The first remote station returns EOT if no poll data exists. The main system device sends a polling signal to the second remote station after a polling period (200ms) has elapsed after sending the first polling signal Poll-SQ.
Send Poll-SQ. Furthermore, what is Paul Data?
This is attention data from the display and error status data when a command ends abnormally. FIG. 5B is a diagram showing a polling sequence when poll data exists. The remote station receives the polling signal Poll− under the condition that poll data is present.
When receiving SQ, sends poll data text. Upon receiving the poll data text, the main body device returns an acknowledgment ACK ₁ , in response to which the remote station sends an EOT. FIG. 6 is a diagram showing the message format. FIG. 6A is a diagram showing the format of the selecting signal Sel-SQ, where SA(S) is a station address for selection, DA is a unit address, and EOT and ENQ are line control characters. SA(S) can take a value from XC ₀ to XCF, and DA can take a value from X80 to X8F. Figure 6 (b) is a polling signal
FIG. 2 is a diagram showing the format of Poll-SQ, and SA
(P) is a station address for polling, and can take a value from X80 to X8F. FIG. 6C is a diagram showing the format of a command text when one command is transferred. In Figure 6 C, DLE,
STX and ETX are line control characters, CC is the CCW command code, F is the CCW flag, and CNT is the CCW command code.
Each shows the CCW byte count.
Further, in read-related commands, there is no write data or control data. FIG. 6D is a diagram showing the format of command text when two commands are transferred at the same time. The first CCW is a control command, and the next
If the CCW is a control-type command, write-type command, or read-type command, and if the first CCW is a write-type command and the next command is a control-type command or read-type command, the two commands are combined into one. can be transferred using a single command text. In FIG. 6D, the position of the second command can be known from the value of the CNT part of the first command. FIG. 6E shows the format of the read data text. FIG. 6 is a diagram showing the format of poll data text. The sense byte field is made up of 16 bytes, and is enabled when the unit check status is a logic '1' in the device status byte; In the case of "0", the sense byte field becomes all "0". Line control characters include those shown in the table below.

〔Effect of the invention〕

As is clear from the above explanation, the input/output control method of the present invention has the following features: (a) The processing program and the management program control the peripheral devices connected by the channel interface and the devices of the remote station using exactly the same method. (b) Since not only command codes but also flags and byte counts can be transferred to a remote station, general-purpose control of the device is possible, and arbitrary input/output can be performed. The device can be connected as a remote station device, and (c) multiple commands can be transferred at the same time, so processing speed can be improved.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the outline of the program according to the present invention, FIG. 2 is a diagram showing the data flow of the control area, FIG. 3 is a diagram explaining the registration flag of the SIO queue table, and FIG. 4 is a diagram showing the present invention. 5 is a diagram illustrating the polling sequence in the present invention. FIG. 6 is a diagram illustrating the message format in the present invention. FIG. 7 is a diagram illustrating the device address and station in the present invention.・A diagram showing the relationship between addresses/unit addresses, FIG. 8 is a diagram explaining the device status byte and channel status byte, and FIG. 9 is a diagram showing the processing performed by the interface control section of the channel control program in the present invention. FIG. 10 is a diagram explaining the processing performed by the line control section of the channel control program in the present invention, FIG. 11 is a diagram explaining the selection process in the present invention, and FIG. 12 is a diagram explaining the command and FIG. 13, which is a diagram showing the text creation process, is a diagram explaining the polling process in the present invention. DESCRIPTION OF SYMBOLS 1... Communication control device, 2... Modem, 3... Communication line, 4... Remote station channel, 5... Remote station processor, 6... Display, 7... Printer, 8...
...Flotspi disc device.

Claims (1)

[Claims] 1. A central processing unit, a remote station channel connected to the central processing unit, a line connected to the remote station channel via a communication control device and a modem, and a line connected to the line. In an information processing system equipped with a remote station, the remote station channel includes an input/output interface control section, a line control section, a subchannel area corresponding to each device, and a device address and registration flag written therein. The input/output interface control unit includes an input/output command queue table having entries and a transmission buffer, and when an input/output command is issued, the input/output interface control unit sends the input/output commands to the corresponding subchannel area.
the next channel address word, the command code in the channel control word corresponding to the relevant input/output instruction,
Writes the data address in the channel control word, the control flag in the channel control word, and the byte count in the channel control word, and also writes the address and address of the device in the entry of the input/output instruction queue table. The line control unit is configured to write a registration flag indicating new registration, and the line control unit refers to the input/output command queue table, fetches a device address with a registration flag indicating new registration, and performs selection based on the device address. When a message is created and sent on the line, and an acknowledgment is received, the command code, control flag, and byte count stored in the subchannel area corresponding to the device address are written to the transmission buffer, and the write system In the case of command or control commands, write data or control
The data is also stored in the transmission buffer, and if the control flag indicates a command chain, check whether the next command can be sent with the same command text, and if possible, send the next channel control word. Writes the command code, control flag, and byte count to the transmit buffer, writes write data or control data to the transmit buffer as necessary, and sends the contents of the transmit buffer onto the line as the same command text. An input/output control method characterized by: