KR920004770B1 - Protocol converting system for computer - Google Patents

Abstract

The system includes a coaxial line signal transmitting and receiving circuit (100) for providing an electrical interface. A byphase communication processing device (101) for exclusively processing the coaxial line signals transmits and receives coaxial line signals and performs arithmetic logic functions. A microprocessor (105) performs the overall controls and provides all kinds of logic functions reguired for the contrls, and a data buffer (104) connects two softwares for (101) and (105) to each other, as well as making data exchanges between the softwares possible. A system data RAM (108) provides the space for the operation of the system. With the system, the facility cost is decreased, and the application field is widened.

Description

System of PROTOCOL Converter for Computer

1a, b, c or diagram of the system for the terminal operation according to the present invention.

2 is a hardware diagram of the present invention.

3 is a configuration diagram of a system showing a control unit connection operation method of a conventional terminal implemented using a personal computer.

4 is a frame structure of a biphasic signal.

5 is a structure of a terminal control area (TCA) of a data buffer RAM during a second step.

6 is a structure of a System Network Architecture (SNA) message used for communication with a host computer.

7 is a structure of the transmission header during the sixth.

8 is the structure of the request / response header during the 6th.

9 is a flow chart according to the present invention.

Table 1 lists the coaxial transmission control commands and transmission control responses.

Table 2 is a list of DFT (Distributed Function Terminal) Synchronous Commands and Synchronous Responses.

Table 3 lists the data stream commands for asynchronous terminals.

Table 4 is a list of SCS (SNA Character String) control codes.

* Explanation of symbols for main parts of the drawings

20,50,70: host computer 21,51,71: control unit

3 to 5, 22 to 24, 52 to 54, 72 to 74: Converter 6, 8, 10: Synchronous monitor

7,9,11: synchronous printer 75 to 84: modem

25 to 39, 55 to 60, 85 to 89: Terminal 100: Coaxial signal transmission and reception circuit

101: bi-phase communication processing mechanism (BCP) dedicated to coaxial signal processing

102: instruction code RAM 103: system clock generator

104: data buffer RAM 105: microprocessor unit (MPU)

106: system software ROM 107: asynchronous input, output buffer

108: system data RAM 109: real time clock generator

110: interrupt control circuit 111: asynchronous RS-232C interface

112: asynchronous transmit and receive clock generator

The present invention relates to a computer terminal, and more particularly, to a terminal connecting apparatus for connecting an asynchronous terminal using an asynchronous communication method to a general host computer communicating with the terminal in a synchronous communication method.

3 shows an example in which a conventional terminal implemented by using a personal computer (PC) is connected to and operated by a general control unit (CU). The personal computer (3, 4, 5, 6) is shown in FIG. The conventional terminal implemented by using, 7 ,, 8, 9, 10, and 11 is a connection method according to the control unit 2 and the Distributed Function Terminal (DFT) protocol. 1) By applying the communication method according to the SNA (System Network Architecture) protocol, the application service message received from the user application program operating on the host computer is displayed on the screen or printer, or the application service message input by the keyboard. Performs the function of sending a to the application program.

In more detail, the terminal implementation method using a personal computer is described in more detail. A coaxial interface device for connecting a coaxial line connected to a control unit is added to the personal computer, and the function of the terminal is removed from a disk or floppy diskette of the personal computer. By starting the program in charge, the personal computer screen, keyboard and printer are used as terminals.

However, these conventional screens, keyboards, and printers are connected to a main body including a microprocessor, memory, disk, diskette device, screen / keyboard input, output control device, and printer control device to display screen control functions, keyboard input processing, and printer. Since the main body is in charge of output control functions, there was a problem that the user had to use all of the above-mentioned devices which are not directly useful in view of the user's purpose, even when the user simply wanted to use a personal computer as a terminal for inputting and outputting application data. .

In this way, when the terminal is implemented using a personal computer, the control unit is connected to the place where the personal computer is located in a coaxial line in a one-to-point manner. The number of wires also increased proportionally, making it difficult to maintain and costly for construction.

In addition, due to the disk, diskette, and memory of the DOS system program for the basic personal computer configuration, the cost of the terminal is more expensive than its purpose, and the maximum extension distance of the coaxial line is limited to about 1.5 kilometres (KM). For this reason, there is a problem that it cannot be disposed away from the control unit over this distance.

The present invention conceived in view of such a problem, the conventional personal computer described above in that it is connected by a coaxial line with the control unit to communicate in a manner according to the DFT protocol and the host computer in a manner according to the SNA protocol It is the same as the case of using a terminal, but using an asynchronous CRT (Cathod Ray Tube), a keyboard terminal or an asynchronous printer as the data input / output device, the present invention can simultaneously connect up to 5 asynchronous terminals. There is a big difference in the fact that by connecting in an asynchronous communication method can provide a terminal that can fully utilize the inexpensive and wide application of the asynchronous communication system.

In addition, the present invention can be configured with only the minimum hardware and software support required to operate as a terminal, thereby providing a terminal at an optimum low cost for the purpose.

In other words, as shown in FIGS. 1A, 1B, and 1C, the protocol converters 22-24, 52-54, 72-74 are all located close to the large trolley unit and are asynchronous where the user is. If the distance between them is close enough by placing terminals 25 ~ 39,55 ~ 60,85-89, connect them simply by twisted pair line according to EIA RS-232 connection standard. Inexpensive and wide range suitable for real-time application by connecting via LAN system or LAN system that provides asynchronous communication method, asynchronous communication system consisting of modem (75-84) and telephone line (PSTN) or public data communication network (PSDN) It is to provide a terminal dispersion system having an application range.

In addition, when using a LAN or a public data network as an asynchronous communication system, a conventional terminal must be connected coaxially with the control unit by using a service function and a management function of the communication network that the communication system originally has. In addition to solving the complexity and maintenance difficulties of the communication line, it can be used to provide a more economical and distributed terminal system that can use various services as the function and performance of such asynchronous communication system evolves in the future.

Hereinafter, the configuration of the present invention will be described in detail with reference to the accompanying drawings.

3 is a hardware block diagram according to an embodiment of the present invention, in which the present invention provides one data buffer 174 that is not connected to a peripheral device by data / address buses DATAl / ADDl and DATA2 / AUD2. Sending, receiving and transmitting coaxial signals required to communicate with the control unit in association with two microcomputers, ie peripherals and system firmware, for connection via the coaxial line with the control unit. Asynchronous terminal and communication function between the coaxial signal processing dedicated biphase communication processor (BCP) 101 and the host computer of the present invention, which provides all the computational logic functions for the operation of the software executing the DFT protocol. Software that performs SNA protocol to communicate with host computer in association with data input / output control function In software that operates to control the data input and output with other languages asynchronous terminal includes a microprocessor unit (MPU) (105), which provides all functions necessary logical operations.

Coaxial signal processing-only bi-phase communication processing mechanism (BCP) 101, which operates by receiving clock signal CKL2 from one of the system clock generators 103, can communicate with the control unit according to the DfT protocol. The instruction code RAM 102 and the microprocessor unit (MPU) 105 are also connected by data / address bus (DATAl / ADDl). Software executed using the microprocessor unit (MPU) 105 and the data buffer 104 serving as a window for exchanging data or exchanging all information required to connect the two softwares. It is connected by a data / address bus (DATA2 / ADD2) and provides an electrical interface connecting the present invention to a control unit. Coaxial signal transmission, and is connected by a coaxial cable data bus (DATA3) configure the receiving circuit 100.

On the other hand, the other microprocessor unit (MPU) 105, which is operated by receiving the clock signal CLKl from the system clock generator 103, is used for all variables and stacks used by the system software operating by using the clock signal CLKl. By restricting the input and output of the system data RAM 108, the real-time clock generator 109 providing storage, the host computer and the asynchronous terminal, and the software responsible for the communication function according to the SNA protocol, the asynchronous terminal is controlled by the host computer. Is transmitted and received via the system software ROM 106 and the asynchronous RS-232C interface 111 in which software for operating in the same manner as the terminal of the terminal and software for allowing the asynchronous terminal to communicate with the present invention are stored. Memory that temporarily stores all data so that smooth asynchronous communication can be achieved EIR RS-232C method by receiving time information (CLK5) required for sending and receiving character unit data asynchronously from asynchronous input and output buffer 107 and asynchronous transmission and reception clock generator 112 providing a place. Asynchronous RS-232C interface 111 which provides five asynchronous communication ports by in charge of transmitting and receiving asynchronous characters for asynchronous communication according to the above, and transmitting and receiving electrical signals necessary for transmitting and receiving the same. As described above, the data buffer 104 and the data / address (DATAl / ADDl), which are also connected to the data / address buffer (DATA2 / ADD2) on the coaxial signal processing-only bi-phase communication processing mechanism (BCP) 101 side, are configured. It is.

Next will be described in detail the operation and effect of the present invention having the hardware configuration as described above.

Communication made with the control unit in the connection method according to the DFT protocol to be described first is performed by the software stored in the instruction code RAM 102 and transmits the coaxial signal to the biphase communication processor (BCP) 101 dedicated to the coaxial signal processing. , Using the receiving circuit 100 and the data buffer 104.

Here, the biaxial communication processing mechanism (BCP) 101 dedicated to coaxial signal processing, which operates by receiving the clock signal CLK2 from the system clock generator 103, may include firmware, a real-time generator, and a data buffer index pointer for coaxial signal processing. Is included in the biaxial signal format having a frame structure as shown in FIG. 4 by receiving a coaxial signal through a coaxial signal transmission and reception circuit 100 which provides an electrical interface connecting the present invention and a control unit. To receive the coaxial transmission control command and the coaxial transmission data included in the data or to receive the data to be received on the coaxial line according to the biphasic signal format. And a coaxial data buffer, which is formed in the data buffer RAM 104, Terminal control area (TCA) and DFT messages are used to control the present invention by writing a control command according to the DFT protocol or to read the present information when the present invention writes information related to its state. It is divided into two parts.

Accordingly, the software stored in the instruction code RAM 102 stores the coaxial data buffer index pointer in accordance with the coaxial control command interpreted by the coaxial line processing processing mechanism (BCP) 101 dedicated to the coaxial signal processing. When the terminal control area (TCA) storage area is designated, the DFT message received from the control unit is communicated to the data buffer 104 by communicating with the control unit according to the DFT protocol by writing a DFT command therein. Software to operate using a microprocessor unit (MPU) 105 and a hardware device connected to the data / address bus (DATAl / ADDl). SNA notified or written to data buffer 104 by software associated with this microprocessor unit (MPU) 105. By making the message a DFT message and sending the guts to the unit, this alias communicates with the guts controller by the DFT protocol.

On the other hand, the present invention communicates with the application program on the host computer according to the SNA protocol to convert the data input from the asynchronous terminal to the data to be output to the asynchronous terminal in the form of the application service message, the SNA communication function is a logical unit ( Between the present invention as a Logical Unit and a logical unit on a host computer to form a session, a reliable and stable virtual circuit, and to the terminal and the function performed between the users, i.e., the invention, through the virtual circuit. This means providing a service for transmitting an application service message between a corresponding application program and an application program running on a host computer.

Communication with the host computer of the present invention based on the SNA protocol will be described in detail in the following description of the SNA message structure.

6 illustrates the structure of an SNA message used in the present invention to communicate with a host computer according to the SNA protocol. A single SNA message includes a transmission header 180 and a basic information unit (BIU). (190) and the Application User Structure (AUS). The SNA message has a hierarchical structure. The SNA communication function is composed of a data transmission function and a session control function. The functions also have a stack of interrelationships, meaning that they each perform their function using independent messages.

FIG. 7 illustrates the structure of a transmission header that provides information for a transmission service of a message in an SNA communication function. This is to ensure that a basic information unit is safely and quickly delivered to an accurate destination. If the message is long, the buffer of the communication device is small in transmitting the long data generated by the communication network for the SNA message transmission service having the communication distance, performance, and function according to the configured communication device and communication medium. In order to prevent the problem of not being able to function as a buffer for data relay, or to correct an error in transmission of long data when using a low speed communication medium, it may take a long time to retransmit the long data. It is preferable to divide the data into a plurality of segments.

The structure thereof is described in detail as follows.

The Main Distributing Frame (MDF) 201 indicates whether the entire basic information unit to be transmitted through the SNA message and the segment of the basic information unit contained in the currently transmitted SNA message are the beginning or the middle of several basic information unit segments. By distinguishing whether it is the last segment, the basic information unit segment received by the receiving side of the basic information unit is reconnected to provide information for making and receiving one basic information unit.

Expedited Flow Indicator (EFI) 205 is set to "1" when the basic information unit means emergency control data so that the corresponding SNA message is preferentially received regardless of the reception wait state of the previously transmitted SNA message. To be delivered to the side.

The LDAF (Local Destination Address FieId) 205 specifies the sending and receiving side addresses of the SNA message, and the LOAF (Local Origin Address Field) 206 specifies the sending and receiving side addresses of the SNA message.

Sequence Number Field (SNF) (207, 208) indicates the order in which SNA messages are sent from the sending side to the receiving side, thereby reconnecting segments of the basic information unit received at the receiving side so that the original basic information units can be received. It is possible to distinguish duplicate SNA messages that may be caused by information and retransmission, thereby providing information that allows the reception of the correct basic information unit.

In addition, the structure of the request / response header (RRH) of the basic information unit is shown in FIG. The structure of this request / response header uses the same structure whether the basic information unit is the request basic information unit or the response basic information unit. The structure is as follows.

The Request / Response Indicator (RRI) 220 is set to '1' if the basic information unit is a request basic information unit and is set to '0' if the basic information unit is a response basic information unit. Make it distinguishable.

The RUC (RU Category) 221 indicates a category of functions to support the application service. The categories of functions to support the application service are session control (SC), communication network control (NC) and data flow control (DFC). And functional management data stream (FMDS).

Fl (Format Indicator) 223 provides information for distinguishing the type of the format of the function management data stream (FMDS) when the basic information unit includes the function management data stream (FMDS).

SDI (Sense Data Indicator) 224 is an intermediate communication device detects when an error occurs in the section of the transmission unit of the basic information unit is added to the sense data (Sense Data) that is information about the error that occurred the original basic information unit Set to "1" when changing to the exception basic information unit (Exceptional B1U).

Beginning Chain Indicator (BCI) 225 and End Chain Indicator (ECI) 226 contain information indicating which part of the chain the basic information unit corresponds to, where BCI and ECI are each " 1 ". If "0", this basic information unit is the first chain. If all are "0", the basic information unit is any chain except the first and last of several chains, and they are "0" and "1", respectively. If this means that the basic information unit corresponds to the last chain, and if it is all "1", one of the basic information units means that the transmission of all chains is completed. In this case, when the application service message is difficult to be transmitted as one basic information unit, it is divided into several small units and transmitted. In this case, the application service message corresponding to a small unit has a length of the application service message corresponding to one chain. When a session (logical unit-logical unit session) is formed (called a BIND) between the logical unit of the present invention and the logical unit on the host computer, the logical unit of the present invention is connected to the host computer. The maximum length that can be received from the logical unit is determined and the logical unit of the host computer is determined by determining the maximum length that can be received from the logical unit of the present invention.

The Definite Response 1 Indicator (DRlI) (227), the Definite Response 2 Indicator (DR2I) (229), and the Exception Response Indicator (ERI) 230 are used by the requesting basic information unit to specify the format of the response basic information unit. do.

ERI (Exception Response Indicator) 230 is set to "1" when the response basic information unit is for negative ques- tions containing 4 bytes of sense data, and "0" if the response basic information unit is a normal response basic information unit. Is set to ".

The queued response indicator (QRI) 232 indicates that the response basic information unit for the request basic information unit with this bit set to "1" can be queued in the transmission process. Set to mode "1" in units and response basic information units.

The pacing indicator (PI) 233 is set as the corresponding bit of the requested basic information unit is set to "1" when pacing is applied to the session formed between the logical unit and the host computer logical unit in the present invention. This means that the transmission between the two logical units causes the sender to transmit the SNA message at a speed that the receiver can handle, especially when the communication processing capability of the two logical units is different, especially when the performance of the receiver of the SNA message is lower than that of the sender. It is a promise for speed.

Beginning bracket indicator (BBI) 234 and end bracket indicator (EBI) 235 are used in the request basic information unit. If the application message in the request basic information unit is generated first in one bracket, BBI and EBl The angles are "1" and "0", and if the last occurrence is "0" and "1", respectively, the BBI and EBI are both "0" if it is any one in between. If only one application task occurs for a bracket, all are "1", where bracket is a unit of work that can completely handle one of the user's application tasks.

When CDI (Change Direction Indicator) 236 is set to "1", it means that the transmission direction of the request basic information unit transmitted by the half-duplex transmission / reception method is changed and used only in the request basic information unit.

Enciphered Data Indicator (EDI) 239 is set to "1" when the application service message contained in the required basic information unit is encrypted and is used only in the required basic information unit.

The PDI (Padded Data Indicator) 240 determines that the length of the application message in the required basic information unit is determined in units of eight bytes, and if the length of the application data is not divided by eight, then X "to the next eight byte boundary. It is padded with 0 "and used only in the requesting basic information unit.

The following describes the input and output functions that the present invention should have as a host computer and a terminal in the process of analyzing in detail the meaning of 3270 data stream (3270DS) and SCS (SNA Character String), which are formats of application service messages.

First, as shown in Table 3, the 3270 data stream writes the application data generated by the application program on the host computer into the 3270 terminal screen image buffer, that is, the command group for outputting to the terminal and the user viewed through the terminal. Instructions for largely separating the data input on the 3270 terminal screen image buffer of the present invention into the application program of the host computer, and the input and output of the fields and characters that constitute the unit of the 3270 terminal screen image buffer. Subcommands are divided into two types, which are means for specifying attributes, and more specifically, for specifying input and output functions of the data stream commands described above, and application tasks to be input and output through actual terminals. On the system data RAM 103 of FIG. The present invention having a 3270 terminal image buffer for performing a function as a 3270 terminal for input and output according to 3270, according to the present invention, an application program of a host computer generates application service data and views it in the form of a 3270 data stream. Each time you send to the invention, the corresponding 3270 screen image is changed, and this 3270 screen image is again compared with the actual screen image of the asynchronous terminal, and then only the changed portion is extracted and output to the asynchronous terminal, while simultaneously displaying the actual screen image of the asynchronous terminal. Change it to match the 3270 terminal screen image.

In addition, there is a case where the data input by the user of the asynchronous terminal differs from the 3270 terminal screen image recorded in the asynchronous terminal screen image buffer on the device of the present invention. In this case, the user corresponds to the AID through the terminal. When inputting data (carriage return, new line, etc.), the present invention extracts the difference between the two screen image buffers and makes it a 3270 data stream and transmits it to the application program of the host computer.

Next, when the present invention receives an SCS as shown in Table 4, the command is interpreted to form an SCS printer screen image according to the command, and then output to the printer as it is to be printed.

In addition, the present invention provides a function key that allows a user to control the operation of the present invention from an asynchronous terminal, and if the character code system used by the application program of the host computer is different from the character code system commonly used by the asynchronous terminal, It has the function of converting each other, so that all the data inputted by the user through the asynchronous terminal is transmitted to the application message with 3270 data stream and character code system used by the host computer, and the application program of the host computer The application data is output through the asynchronous terminal in the same way as they are specified by the SCS, which is the 3270 data stream, i.e. in the same form as the SCS and 3270 terminals they wish to use.

As described above, the present invention is composed of the minimum hardware and software necessary for operating the present invention, and communicates with the control unit in a normal manner according to the DFT communication method, and with the host computer in a communication method according to the SNA communication method. Application data is exchanged. In particular, by connecting the starter CRT / keyboard terminals or asynchronous printers with asynchronous communication as input and output devices, it is possible to provide consumers with inexpensive and wide coverage terminals.

Claims (6)

Coaxial signal transmission / reception circuit 100 connected to a control unit to provide an electrical interface, a coaxial signal processing-only biphase communication processing mechanism for providing coaxial signal transmission and reception and all arithmetic logic functions required for communication with the control unit. 101), an instruction load ram 102 in which software for communicating with the control unit is recorded according to the DFT protocol, software for performing SNA protocol for communicating with a host computer, and software for controlling data input / output of an asynchronous terminal. Is performed using the microprocessor unit 105 and the microprocessor unit 105 that provide all of the computational logic functions required for the operation, the software to be executed using the coaxial signal processing-only biphasic communication processing mechanism 101, and Software exchanges data And a data buffer 104 for exchanging all the information necessary to connect the two software, and a software and asynchronous method connected to the data buffer 104 to allow the asynchronous terminal to operate the same as the terminal of the host computer main body. The system software ROM 106 in which the software to communicate is stored, the system data RAM 108 providing storage for all the variables and stacks used by the system software, and the asynchronous RS-232C interface 111. A system of a protocol converter for a computer, characterized by comprising an asynchronous input / output buffer (107) for temporarily storing all the updated data to enable smooth asynchronous communication. The method of claim 1, wherein the protocol converter utilizes a screen control function of the CRT / keyboard of the synchronous terminal through an asynchronous LAN (PS) system and a public data communication network (PSDN) 61, and the CRT / keyboard of the synchronous terminal A system of a protocol converter for a computer, which utilizes key functions to be provided as keys, and uses a print control function of a printer requiring an SCS command as a print control function of a print of a synchronous terminal. 2. The protocol converter of claim 1, wherein the protocol converter is a screen control function of a CRT / keyboard of a synchronous terminal by connecting an asynchronous modem (75-79) (80-84) (85-89) with a telephone line or the like. As a screen control function required by the command, it utilizes the screen control function required by the data stream command and subcommands, and uses the key functions to be provided as keys on the CRT / keyboard of the synchronous terminal. A system for a protocol converter for a computer, characterized by using the print control function of a printer required by an SCS command. 2. The power-on reset signal transmission of claim 1, wherein the coaxial signal processing-only biphase communication processing mechanism (BCP) 101 performs an initialization process of the DFT message to communicate with the DFT communication protocol at the same time as the operation is started. And a program for performing a control unit response wait, a local device session establishment process, and a start operation command, a DFT synchronous command, a message formation and a data reception command confirmation and inbound for a communication function based on the DFT communication method. A system for a protocol converter for a computer, comprising a program for performing a process such as waiting for DFT data transmission. 2. A program according to claim 1, wherein the program of the microprocessor unit (MPU) 105 is started periodically by the dispatcher and is operated by allocating processing power to the SNA communication system between the host computers 20, 50, and 70. SNA message waiting check, inbound SNA message waiting waiting, outbound SNA data request checking, SNA data receiving in the logical unit-logical unit session, BIND command checking, logical unit-logical unit to provide other communication services A system for a protocol converter for a computer, comprising a session establishment, a session establishment success check, and an inbound SNA message transmission waiting check process. 2. The protocol converter according to claim 1, wherein the protocol converter analyzes the outbound data stream received from the application program of the host computer in the SNA message and outputs it to the asynchronous terminal 25-39 (55-59). (25-39) The data input from (55-59) is transferred to the application program of the host computer 20 (50) and 70 in the form of a data stream and transmitted in an inbound SNA message. A system of protocol converters for computers, characterized by being capable of replacing. TABLE 1a

TABLE 1b

TABLE 2

TABLE 3

TABLE 4

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