JPS615652A - Polling control transmission processing system of hdlc procedure - Google Patents

Abstract

PURPOSE:To reflect an accurate content to all commands corresponding to a station by using a sense command provided to a command string so as to rewrite a control information storage means. CONSTITUTION:A communication controller 20 is provided with a transmission control circuit 23 controlling an outgoing side of a subchannel of a full duplex line, a reception control circuit 22 controlling an incoming side and a control information storage means storing control information of plural terminal devices S1-S3. When transmission data is generated, a CCW string is generated based on control information described in a storage means and a sense command provided in a command string rewrites the storage means. Then when the CCW string is received by the devices S1-S3, the control information is rewritten automatically based thereupon, the rewritten information is used as control information to generate the CCW string for transmission. Thus, always accurate control information exists in one area and the accurate content is reflected upon all the commands corresponding to the devices S1-S3.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a polling control method using a communication control device, and particularly relates to a polling control method using a communication control device as a primary station (
P station) When multiple terminal devices connected to the communication control device are used as secondary station controllers (S station), a full-duplex line connection is established between the communication control device and the plurality of terminal devices using the HDLC method. Second, a plurality of pieces of transmission data are efficiently transmitted from a P station to a plurality of S stations.

For example, as shown in FIG. 6, when there are multiple terminal devices connected to the line from the communication control unit ccU,
This communication control unit CCU is connected to the primary stay 9372.
8 secondary stations, and multiple terminal devices connected to this multipoint line as 8 secondary stations.
When polling according to the procedure, the communication control device C, which is the P station,
If there is no transmission data in the CU, it is necessary to sequentially poll the eight terminal devices on this multipoint line. In this case terminal equipment! is an always-on N
RM (Normal Re5ponse Mod
NDM (Normal D 1ac-one) which is normally disconnected but becomes connected with the 8 stations of
There are two types of eight stations (in cted mode), and it is necessary to poll these in sequence.

There are two types of polling: a data ball (calling in received data) for the 8 NRM stations, and a contact poll for the 8 NDM stations (inquiry about the transition from NDM to N, which is in a connected state, and RM).

Generally, after data balls are sent to all NRM stations a specified number of times, the operation of contact polling to NDMI stations is repeated.

The data ball is the P-S command (Poll Bit).
F4-fS response (F4-fS response) is sent from the eight stations to request a response.
5upervis with inal Bit.

This process waits for received data until it receives a ry command (command indicating transmission right relinquishment).

Contact pole is SNRM command with P (Poil
UA response with F (Unnumbered Acknowledgment with Final Bit) is sent and a response is requested.
This is a process of waiting for the reception of a message (indicating that the mode has been changed to NRM mode) or the occurrence of a timeout.

These processes need to be performed continuously while no transmission data is generated.

When performing input/output control using a communication control device, it is necessary to adhere to standard channel interfaces.

[Problems to be solved by the invention]

Incidentally, after sending an S command with P to eight NRM stations, there may be cases where transmission data exists for these eight stations on the communication control device side. In such a case, for example, the seventh
As shown in the figure, packs (in this example, V
rit'e punk) and send it. This puncture starts with a control C command, which reads the control information C necessary for transmission, learns the state of the other station, and performs control accordingly. A series of sequence numbers are assigned to the commands of this pack, and when sending Write commands in the same pack to the same eight stations, send them in the order of this sequence number. It will be necessary to show For example, if you press Write for 31 stations, first write
After sending the ite commands Na, 1 and NCL2, perform other search ring control for the S2 station, and then when sending the W'rite pack to the S1 station again, this time the
It is necessary to execute the Write command and subsequent steps. Therefore, conventionally, each time this one pack is completed, the host CPU is notified of the sequence number of the command that has been executed, and the host CPU rewrites the control information C based on this report. It is necessary to instruct Kuzuyo to run from number 3. If this number is not specified, the command with sequence number 1 will always be executed.

Therefore, there is a problem in that the load on the host CPU increases to control this rewriting.

In addition, in order to realize P cycle operation that supports 8 NRMO stations using the HDLC procedure, if a failure occurs in multiple transmission data 1 for multiple 8 stations on the communication IIJ' control equipment side, which is the P station. In order to eliminate processing by channel interrupts and increase line efficiency, it is necessary to convert data that can be transmitted into commands and issue them as two series of ccWjl. In this case, it is efficient because once the output 0 is issued to the first CCW, the subsequent CCW sequences are executed from the communication control device 1. However, all the data pointed to the CCW corresponding to the eight stations, such as pigeon lofts, where it is necessary to receive responses from the eight destination stations, modify the control information, and change the sequence number of the command incorporated in the CCW column. It is necessary to rewrite the data, which makes the processing of the host CPU very complicated, and the C
When a CW train is created, the control information is not rewritten, so there is a problem in that such an efficient CCW train cannot be created.

[Means for Solving the Problems and Their Effects] In order to solve the above-mentioned problems, in the polling control transmission processing method of the HDLC procedure of the present invention, a plurality of secondary stations connected to a subchannel of a communication control device On the other hand, in a polling control method that performs polling, a transmission control means for controlling the output side of a subchannel of a full-duplex line, a reception control means for controlling the input side of the subchannel, and control information for the plurality of secondary stations. A control information holding means is provided to hold the control information, and when transmission data is generated, a CCW string is created based on the control information written in the control information holding means, and the control information holding means is rewritten by the sense command provided in the command string. It is characterized by being made possible.

As a result, when the CCW string is received by eight stations, the control information is automatically rewritten based on this, and this rewritten information can be used as control information to create the CCW string for transmission, so it is always accurate. Since the control information exists in one area, this exact content can be reflected in all commands corresponding to that station.

〔Example〕

An embodiment of the present invention will be described with reference to FIGS. 1 to 5.

Figure 1 is a configuration diagram of one embodiment of the present invention, Figure 2 is a standard CCW
FIG. 3 is a block diagram of a frame of the HDLC procedure, and FIGS. 4 and 5 are diagrams explaining its operation.

In FIG. 1, 10 is a host CPU, 11 is a main memory, 20 is a communication control device, 21 is a line control unit, 22 is a reception control circuit, 23 is a transmission control circuit, 24 is a control register,
25 is a microprogram section, 26 is a subchannel head address table, and 27 is a line control section.
28 is a local strain, 29 is a local strain address register, and 81 to S3 are terminal devices connected to the same subchannel.

The line control unit 21 sequentially performs polling control on the terminal devices 81 to S3 and transmits and receives data.
It has a reception control circuit 22, a transmission control circuit 23, an input/output command receiving circuit (not shown), and a transfer processing circuit (not shown).

The microprogram section 25 stores a microprogram for controlling this communication control device 20, and also has a subchannel head address in which the storage destination head address of control data necessary for polling control is written. - A table 26-1 is provided, and also includes an interrupt code classification section (not shown), a command classification section (not shown), a transfer instruction section (not shown), and the like.

The line control word section 27 is provided for each subchannel and is divided into a receiving side and a transmitting side, and stores, for example, a CRC check code and is provided with a data buffer.

A local strain 28 is provided corresponding to each subchannel and is divided into a receiving side and a transmitting side, and commands are sent and control information is sent.

The terminal device S+-33 is connected to the communication control device 20 through the same subchannel of the full-duplex line #0, for example, and is connected to the communication control device 20 using the HDL
Data is sent and received using the C procedure.

Next, the standard CCW column (pack) will be explained with reference to FIG.

As shown in Fig. 2(a) to (C), there is a Wri in the bank.
te pack, 'Write Po11 back, Pa1
There are l packs etc. Write puncture is used when transmission data is generated when a command with P is sent to 8 stations and no response with F is sent back yet. Write Potl pack is used when there is transmission data for 8 stations and 8 stations have sent back responses with F, and there is transmission data from this side, Po1l back is used when there is no transmission data for 8 stations. However, it is used when sending commands with P.

What is important in the present invention is that the control (C) information and additional information area pointed to by the Control C command at the beginning of each pack and the area pointed to by the Sense C command are This means that they are the same.

Here, the control C command indicates passing control information from the host CPU 10 to the communication control device 20,
Also, the sense C command is sent from the communication control device 20 to the host C.
It shows that control information is passed to PU10.

Next, the operations of these two commands will be explained.

The control command of the HDLC procedure performs the following processing.゛,■゛ When an input/output command is issued from the host CPU 10 to the line control unit 21, an input/output command receiving circuit (not shown) is activated and an interrupt code for the microprogram is created.

■ The microprogram started by the line control unit is
A command classification unit (not shown) classifies commands.

■ When a control command is used, the command is classified by the command neck (not shown).

■ In the case of a control command, the transfer instruction unit requests the line control unit 21 to transfer control information, and at the same time, the PSQ of the local strain 28 is placed in a state where it is waiting for control information transfer (
PSQI).

Furthermore, the mode of the line control word section 27 sets the transmission or reception mode to transfer wait mode depending on the line to which the command has been issued.

(2) The line control unit 21 transfers control information from the main memory 11 to the local strain 28 using a transfer processing circuit (not shown).

4 ■ The microprogram section 25 uses PSQ as described above.
Since the value is 1, the transferred control information is set in the local strain 28, and then the same process as in (2) above is continued for the size of the control information.

■ In this way, the local strain of control information 2
When the transfer to 8 is completed, this control command is terminated. 1
[Also, the sense command of the HDLC procedure performs the following processing.

(2) When an input/output command is issued from the host CPU I O to the line control unit 21, the input/output command receiving circuit is activated and an interrupt code for the microprogram is created.

(2) The microprogram activated by the line control section 21 is classified by the interrupt code classification section.

(2) When the interrupt content is input/output command reception, the command is classified by the 4-command classification section.

■'In the case of a sense command, the transfer instruction unit requests the line control unit 21 to transfer control information, and at the same time sets the PSQ of the local strain 28 to wait for control information transfer (PSQ
I). Furthermore, the mode of the line control word section 27 sets the transmission or reception mode to transfer wait mode depending on the line to which the command has been issued.

■'The line control unit 21 is connected to the main memory 11 by the transfer processing circuit.
Transfers additional information and control information to.

(2) The micro-program unit 25 continues the same processing as in section (2) for the size of the control information as described above (because PSQ is 1).

■'When the transfer of control information to the main memory is completed in this way, this sense command is terminated. .

Furthermore, the frame structure of the HDLC procedure is shown in Figure 3.
is a flag sequence in which a specific F pattern is written, and the period between F and F constitutes one frame. A is an address field that specifies the secondary station to which data is transferred, p! This control field is used to set control information such as command/, response type, and sequence number. I is an information (data) field, and Fe2 is a frame check sequence for error detection.

For each of the 28th iO(a) to (C), the control information C is passed to the communication control device 2o by the control C as described above. Based on this control information C, the communication control device 20 transmits the transmission data to the third command if it is a Write command.
For the frame shown in the figure, create an I command without P in the ■ field, and create and send an S command with P if it is a Po1l command.The control information is used to create the address field and control field. In addition to the contents to be stored in these address fields and control fields, the status of the own station and the eight stations, etc. are stored.

Further, in the case of a Pa1l command, the control information C held at that time is notified to the incoming subchannel.

In each pack, additional information is added to the control information C held at that time by the sense C command, and the added information is transferred to a designated area on the host CPU 1'0 side. At that time, some of the host's areas are not updated.

Next, the present invention will be explained in detail.

(1) First, when transmission data is generated on the communication control device 20 side, based on this data, as shown in FIG. 2(b),
Create a Write Poll pack to activate this CCW column. Prior to this, a ReadCCW sequence shown in FIG. 4 is issued to the ingress side in advance.

(2) After starting the Write Po1l Punk, M
When transmission data is generated until receiving the F-sponse transmitted from the S station, based on that data, the
Create the Write puncture shown in And the N of the last CCW of the first Write Po1l punk published.
Change op to TIC (branch command) and start the first Wri
Point at the beginning of the TE pack. And the first Wr.
Ite Punk's last CCW Nop is TI again.
c, and point the branch destination to the beginning of the second Write bank. As a result, on the output side, a CCW train as shown in FIG. 4 is created and operated. Then, the sense command at the end of each pack rewrites the control information related to the matter processed by the puncture into the control information area on the output side of the local strain 28.

Then, the first control command of the next pack looks at the same control information area as this sense command and creates control information. For example, when a Write command with sequence number 1.2 is executed during the first write back, the sense command rewrites this to the control information area. Therefore, this is created so that the control command reads this at the next Write puncture and the Write command with sequence number 3.4.- is executed.

(3) By the way, when the response with F is received from the 8th station, the ingress side investigates the validity based on the control information C passed from the egress side, and thereafter skips the Read command and sends the sense C.
This control information C with additional information is transferred to the host CPU IO using a command.

(4) As a result, when the host CPU10 learns of receiving the response with F, it sends a ReadC on the input side as shown in Figure 4.
After reissuing the CW sequence, if there is transmission data to the 8 stations that should send the command with P, create a WritePall pack, if there is no transmission data, create a Pa1l bank, change the Nop of the final pack to TIC, and then Point at the beginning of the puncture.

(5) By repeating the above steps, commands can be sent without interruption as long as there is data that can be sent.

In addition, as shown in FIG. 5, on the outgoing side, by making the areas specified by the control command and sense command to the same S station the same, when it is necessary to change the sequence number to be transmitted, the host CPU10 Therefore, all the control information such as the value of the sequence number of the transmitted command can be changed just by changing the area, so that the control command can be executed using accurate control information.

〔Effect of the invention〕

According to the present invention, since the areas specified by the control command and sense command of the same station are the same, if the control information is rewritten with the sense command at the end of the puncture,
The first control command of the next puncture can create a CCW sequence that can be continuously controlled. Furthermore, when it becomes necessary to change the sequence number (receive number) to be transmitted, by changing the area using the host CPU, all the sequence number values of the transmission command can be changed.

[Brief explanation of the drawing]

Figure 1 is a configuration diagram of one embodiment of the present invention, Figure 2 is a standard CCW
An example of a column, FIG. 3 is a diagram of the frame configuration of the HDLC procedure,
4 and 5 are diagrams for explaining the operation of the present invention, FIG. 6 is a diagram for explaining polling, and FIG. 7 is a diagram for explaining the problems of the prior art. In the figure, 10 is a host CPU, 11 is a main memory, 20 is a communication control device, 21 is a line control unit, 22 is a reception control circuit,
23 is a transmission control circuit, 24 is a control register, 25 is a microprogram section, 26 is a subchannel head address table, 27 is a line control word section,
28 is a local strain, 29 is a local strain address register, and S+-33 is a terminal device connected to the same subchannel.

Claims (1)

[Claims] 1. A plurality of 2 connected to subchannels of a communication control device
In a polling control method for polling the next station, a transmission control means for controlling the output side of a subchannel of a full-duplex line, a reception control means for controlling the input side of the subchannel, and the plurality of secondary stations A control information holding means for holding control information is provided, and when transmission data is generated, a CCW string is created based on the control information written in the control information holding means, and the control information is held by a sense command provided in the command string. A polling control transmission processing method for an HDLC procedure, characterized in that the means is rewritable. 2. The polling control transmission processing method for the HDLC procedure according to claim 1, wherein the control information holding means is configured to be rewritable by a host CPU.