JPH0467825B2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention enables data communication of attached equipment used by connecting to a transmission line connected to a terminal device that is to perform data communication using the start-stop synchronization method. Concerning the automatic setting method of conditions for

(Prior Art) Data communication systems that process and transmit data have come to be widely used for various purposes in recent years. method,
Certain conventions (communication regulations) are established between sending and receiving devices regarding data transmission (coding format), transmission speed, synchronization method, bit length, type of parity check method, and other necessary matters. This is done in accordance with the communication rules mentioned above.For example, in cases where there is no synchronization element in the transmission line itself and data transmission at a relatively low transmission rate is permitted. It is well known that a start-stop synchronization method has been widely used for data transmission, in which a start bit and a stop bit of 1 bit length are added before and after the data to be transmitted. That's right.

(Problem to be Solved by the Invention) Now, data transmission in data communication is performed according to predetermined communication rules as described above, so data transmission is performed according to a certain communication rule. If you plan to attach or add other equipment, devices, or circuits to the data transmission line that is currently being used, the aforementioned equipment, devices, or circuits that should be added to the data transmission line must also be included. Of course, it must be made to operate in accordance with the predetermined communication rules mentioned above.

For data transmission lines that transmit data according to a specific communication protocol as mentioned above,
One of the conventional examples of devices that are attached or used with other devices, devices, or circuits is a device that can display the status of data being transmitted on a transmission line on a display. However, in order to operate the conventional additional device described above by connecting it to a data transmission line that transmits data according to a predetermined communication protocol, it is necessary to add the additional device. In order to enable the device to operate in accordance with the communication rules described above,
Since it was necessary to manually enter the settings for the operating requirements of the additional device into the additional device one by one, the above-mentioned conventional additional device was complicated to handle.

(Means for Solving the Problems) The present invention provides conditions for enabling data communication of an accessory device used by being connected to a transmission line connected to a terminal device on which data communication using an asynchronous method is to be performed. In this automatic setting method, the first data whose least significant bit is "1" is transmitted as data following the start bit to the transmission line to which the accessory equipment is connected, and then the first data is transmitted as the data following the start bit. 2
If the number of "1" bits in the first data is an odd number, the number of "1" bits is an even number, and the number of "1" bits in the first data is an even number. means for transmitting data in which the number of "1" bits is an odd number in the case of an even number, following the start bit; means for determining the baud rate and sampling timing for data readout by measuring the time length of the start bit transmitted through the transmission line; A means for determining the type of parity check method adopted in a data communication system including a transmission line, depending on the manner of adding parity bits, a plurality of pre-prepared bit patterns, and the above-mentioned method. The bit patterns in the first information signal containing the first data and the second information signal containing the second data are compared to determine the communication adopted in a data communication system including a transmission line. Enables data communication of an accessory device, comprising means for estimating a protocol and means for setting operating conditions in the accessory device so that the accessory device can operate in accordance with the estimated communication protocol. This method solves the conventional problems by providing an automatic setting method for the conditions.

(Example) Below, with reference to the attached drawings, automatic conditions for enabling data communication of accessory equipment used by connecting to a transmission line connected to a terminal device to which data communication using the asynchronous method is to be performed will be explained. The specific contents of the setting method will be explained in detail.

FIG. 1 is a block diagram showing a schematic configuration of an embodiment of a method for automatically setting conditions that enables data communication of accessory devices according to the present invention, and FIG. FIG. 3 is a block diagram showing an example of the structure of the attached equipment.

In FIG. 1, HC is, for example, a host computer, TA is, for example, a terminal device, and T is a data transmission line.
The HC, the terminal device TA, and the data transmission line T constitute a data communication system configured according to a specific communication protocol.

The host computer HC shown in Figure 1
and the terminal equipment TA on the transmission line T.
The block indicated by ADA represents an accessory device ADA that is used by connecting to a data communication system, but in the following explanation, this accessory device ADA is defined as a The above-mentioned host computer HC and terminal device
All information signals transmitted on the data transmission line T in the data communication system constituted by the TA and the data transmission line T are applied to the data transmission between the host computer HC and the terminal device TA described above. It is configured with functions that allow it to perform operations and record data in accordance with established communication regulations, and to reproduce the recorded information signal and output it to the transmission line T. The configuration is shown in Figure 3.

In Fig. 3, 1 is an interface with the terminal device TA, 2 is an interface with the host computer HC, 3 is a large-scale integrated circuit for communication, and 4 is an interface with the host computer HC.
5 is a central processing unit, 5 is an information signal storage device (for example, a magnetic recording and reproducing device that performs recording and reproduction using a magnetic recording medium such as a floppy disk), 6
7 is a read-only memory (ROM), 8 is a random access memory (RAM), and 9 to 11 are data buses.

The attached device ADA communicates it with the host copier HC and the terminal device TA according to certain communication protocols.
By connecting to the data transmission line T between the The information signal from the recorded magnetic recording medium is reproduced from the information signal storage device 5 to the above-mentioned accessory equipment.
The information signal sent from the ADA can be used as a substitute for the information signal sent from the host computer HC.
In the HC, the information signal sent from the accessory device ADA described above can be used as a substitute for the information signal sent from the terminal device TAB, and the accessory device ADA equipped with the above-mentioned functions is
It can be used effectively for many purposes.

Now, as mentioned above, the accessory device ADA is used in a data communication system consisting of a host computer HC, a terminal device TA, and a data transmission line T according to a certain communication protocol. All information signals being transmitted on the data transmission line T can be recorded, or the recorded information signals can be reproduced and output to the transmission line T, and the information signals can be used to control the host computer HC or terminal device.
The attached equipment ADA that can operate TA includes the above-mentioned host computer HC and terminal device.
It is necessary to be able to operate in accordance with the specific communication protocol applied to data transmission between TAs, but there are various communication protocols applied to data transmission between the host computer HC and terminal device TA. Miscellaneous.

The attached equipment ADA is designed to be used for data transmission so that it can be easily connected to the transmission line T to which any of the miscellaneous communication regulations mentioned above are applied. When an accessory device ADA is connected to line T, the operation mode of the accessory device ADA is automatically set to correspond to the specific communication protocol applied to data transmission on transmission line T. Something is desired.

For this purpose, in the present invention, an accessory device used by connecting to a transmission line T connected to a terminal device TA on which data communication based on the start-stop synchronization method is to be performed.
As an automatic setting method for the conditions that enable ADA data communication, the first data whose smallest digit bit is "1" as the data following the start bit is sent to the transmission line T to which the attached device ADA is connected. Then, if the number of "1" bits in the first data described above is an odd number, the number of "1" bits is an even number, and the number of "1" bits in the first data is an even number. When the number of "1" bits is an even number, a means for transmitting data in which the number of "1" bits is an odd number is provided following the start bit, and the above-mentioned transmission line T means for determining the baud rate and sampling timing for data readout by measuring the time length of a start bit transmitted prior to the first data transmitted to the first data;
The parity check employed in the data communication system including the transmission line T depends on the manner in which parity bits are added to the first data and second data transmitted over the transmission line T. means for determining the type of system; a plurality of bit patterns prepared in advance; and bit patterns in the first information signal including the first data and the second information signal including the second data. By comparison, means for estimating the communication protocol adopted in the data communication system including the transmission line T, and the attached equipment according to the estimated communication protocol.
Attached equipment to allow ADA to perform operations
The above-mentioned problems have been solved by providing a method for automatically setting conditions that enables data communication of attached equipment, which is equipped with a means for setting operating conditions in ADA.

Now, when an accessory device ADA is connected to the transmission line T where data is being transmitted, in order for the accessory device ADA to perform good signal processing, it is necessary to Check the content of the specific communication protocol applied to the data being transmitted over the transmission line T, and confirm that the signal processing in the attached device ADA As mentioned above, it is necessary to follow the same content as the communication agreement.

As mentioned above, the content of the communication protocol that should be the same is the start bit, stop bit, baud rate, and sampling pulse for data readout, assuming that data communication is performed using the start-stop synchronization method. These include the cycle of the parity check, the type of parity check method, and the bit length.

In other words, in accordance with the communication protocol adopted for data communication performed by the start-stop synchronization method, values such as the start bit time length, the number of stop bits, the baud rate, and the cycle of sampling pulses for data reading are determined. However, the data length is different, and the data length is 7 bits or 8 bits.
In addition to the data length of bits adopted, there are also different parity check methods adopted, such as odd parity method, even parity method, and others, but in the method of the present invention, In accessory equipment that is connected to a transmission line connected to a terminal device on which data communication is being performed, the above-mentioned start bit time length, stop bit time length, baud rate, and sampling pulse for data reading are It is used in a data communication system that includes a transmission line T to which attached equipment is connected based on the values of the period, data length, and parity check method employed. In order to be able to estimate the communication protocol that is transmitted using the asynchronous method, two characters having a code form that meets specific conditions are provided to the attached device ADA using the asynchronous method, and the structural characteristics of the code transmitted using the asynchronous method are provided. or,
The communication rules adopted in the data communication system including the transmission line T to which the attached equipment is connected are based on the pattern of two characters having a code form that meets the specific conditions mentioned above. This allows for estimation.

The above points will be explained in detail with reference to the drawings as follows. First, in the code form of the information signal transmitted using the asynchronous method, a 1-bit long start bit b _st is provided for each character (data) to be transmitted. b Specified number of bits of data in _st (7-bit data or 8-bit data)
is followed by a parity bit b _p placed as necessary, followed by a stop bit b _sp of a predetermined length of time (see Figure 2). There is.

The system of the present invention has a configuration that follows the code format of the information signal as described above to be transmitted in the asynchronous system, and has a specific configuration as illustrated in FIG. 2. The first and second information signals configured in accordance with the communication protocol adopted in the data communication system are provided to the accessory device ADA prior to the start of data communication performed using the accessory device ADA. The attached device ADA estimates the communication protocol adopted in the data communication system based on the first and second information signals, and the attached device
It automatically sets the operating conditions of ADA to enable data communication.

By the way, as is clear from the example shown in FIG. 2, the configurations of the first and second information signals described above are as follows. The first information signal is configured to include first data whose least significant bit (LSB) is "1" as data following the start bit _bst , and the first information signal includes first data whose least significant bit (LSB) is "1". In the information signal, when the number of "1" bits in the first data is an odd number, the number of "1" bits is an even number,
Furthermore, when the number of "1" bits in the first data is an even number, the second data such that data with an odd number of "1" bits appears following the start bit b _st It is composed of:

An example of the first and second data that meet the above conditions is the symbol "CR" indicated by OD in hexadecimal.
(Return) is the first data, and the symbol "LF" (line feed), which is indicated by OA in hexadecimal, is the second data. It is a desirable selection example to use "CR" and "LF" in the above example as the first and second data, and as the first and second data shown in FIG. 1. “CR” as the second data,
Indicates when "LF" is used.

As mentioned above, the first and second information signals of the configuration illustrated in FIG. Prior to the start of data communication, for example, when the terminal device TA side (which may be the host computer HC side) sends the data to the interface 1 (FIG. 3) in the attached device ADA via the transmission line T, the above-mentioned 1st and 2nd
The information signals are supplied to the central processing unit 4 via an input port 6 and a data bus 9.

Based on the first and second information signals supplied to the central processing unit 4, the central processing unit 4 determines under what communication protocol the data sent from the terminal device TA to the transmission line T. Large-scale integrated circuit for communication 3
(For example, Matuchipuru, Plutocol, Serial, etc.
controller) to initialize the large-scale integrated circuit 3 for communication to operating conditions compatible with the estimated communication protocol.

Here, first, the attached device is connected via the transmission line T.
Based on the first and second information signals supplied to the ADA, the terminal device TA (or host computer
The reason why the central processing unit 4 can estimate what kind of communication protocol the data sent from the HC) to the transmission line T is transmitted will be described below. When the first and second information signals are arranged sequentially on the time axis, focusing on the state of change in the signal level of the first and second information signals on the time axis, we can see the following: The following matters will be clarified.

Referring to FIG. 2, at the time position t1 of the leading edge of the start bit b _st in the first information signal,
The signal level changes from a high level state to a low level state, and then, at time t2, a state of 1 in the LSB in the first data is detected, but the time length τb from time t1 to time t2 described above indicates the 1-bit length defined in the communication protocol applied to the transmission of the first and second information signals.

Therefore, if this time length τb is known, the first
The baud rate in the communication protocol applied to the transmission of the second two information signals is immediately revealed, and the first and second data are It is clear that it is also readily possible to generate sampling pulses for reading data such that the successive pulses are located approximately in time at the midpoint of each successive bit in .

Furthermore, as data following the start bit _bst , there is a first information signal including first data whose least significant bit (LSB) is "1", and a first information signal containing first data whose least significant bit (LSB) is "1", and If the number is odd, the number of “1” bits is even,
Furthermore, if the number of "1" bits in the first data is an even number, the second data such that data with an odd number of "1" bits appears following the start bit _bst is By detecting the state of the parity bit in the second information signal, it can be determined whether the parity check method specified in the communication protocol applied to the transmission of the first and second information signals is the odd parity method. , it can be determined whether it is an even parity method, another parity method, or a non-parity method.

Furthermore, even if predetermined code formats are selected and used as the first and second data in the first and second information signals, the bit lengths of the first and second data are The presence/absence of parity bits, the bit length, etc. can be selected from multiple types and configured to configure the first and second information signals described above. According to the communication protocol adopted in the data communication system including the line T, the bit patterns of the first and second information signals described above include a predetermined number of different types of bit patterns. It will be possible.

Therefore, for the first and second information signals, the predetermined number of bit patterns described above are stored in the ROM.
7 is prepared in advance, and the plurality of bit patterns prepared in advance and the first and second bit patterns described above are used.
By comparing the bit pattern of the information signal, it is possible to estimate the communication protocol adopted in the data communication system including the transmission line T to which the attached device ADA is connected.

Therefore, in order to enable the attached device ADA to operate according to the communication protocol estimated as described above, the attached device ADA is equipped with a large-scale integrated circuit for communication (e.g., multiple protocol By initializing the serial controller (serial controller) 3 to operating conditions that conform to the communication protocol estimated as described above, the attached device ADA receives the data configured including the transmission line T to which it is connected. It becomes possible to operate according to the communication rules adopted in the communication system.

Now, the data sent from the terminal device TA (or host computer HC) to the transmission line T is
By focusing on the state of change in signal level on the time axis of the first and second information signals, it is possible to estimate the communication protocol according to which the data was transmitted. The reason why the processing can be performed by the processing unit 4 is as described above.The central processing unit 4 stores the first and second information signals supplied thereto in the memory (RAM), and then stores them from the memory. Regarding the read first and second information signals, the state of change in signal level on the time axis in the above-mentioned first and second information signals is checked to determine whether the data sent to the transmission line T is Signal processing is performed to estimate what kind of communication protocol is being transmitted.

For example, the time length τb of the start bit b _st in the first information signal described above is measured when the signal level of the start bit b _st changes from a high level state to a low level state in the central processing unit 4. The number of idle runs of the program is set in the central processing unit 4 from the time when the signal level changes from a low level state to a high level state according to the least significant bit in the first data. It can be calculated by counting in the register provided and multiplying the counted value by the number of steps.

Then, the time length τb of the start bit b _st in the first information signal is as described above,
Since it indicates the 1-bit length stipulated in the communication protocol applied to the transmission of the second information signal,
Based on the time length τb, the central processing unit 4 can immediately determine the baud rate in the communication protocol applied to the transmission of the first and second information signals. Based on the information of times t1 and t5 and time length τb, it is possible to read data in which sequential pulses exist at the time positions of the abbreviations in the center of each successive bit in the first and second data. Data for generating sampling pulses can be set.

In addition, the central processing unit 4 uses the least significant bit (LSB) as data following the start bit b _st.
If the first information signal includes the first data such that is "1" and the number of "1" bits in the first data is an odd number, the number of "1" bits is an even number. In addition, if the number of "1" bits in the first data is an even number, the first data such that the number of "1" bits is an odd number appears following the start bit _bst . By detecting the state of the parity bit in the second information signal containing the second data, the parity check method specified in the communication regulations applied to the transmission of the first and second information signals can be detected. Odd parity method, even parity method, other parity method, or non-parity method.
It is possible to determine whether it is a parity method or not and obtain the resulting data.

It is obtained from various data obtained through arithmetic processing performed in the central processing unit 4, focusing on the state of change in signal level on the time axis in the above-mentioned first and second information signals. The bit patterns are the first and second bit patterns that comply with the communication regulations applied when transmitting the first and second information signals.
A second bit pattern is shown.

By the way, since a plurality of types of bit patterns for the first and second information signals are stored in the ROM 7 in advance, each bit pattern stored in the ROM 7 and the arithmetic processing of the central processing unit 4 are By comparing the bit patterns obtained from the various data obtained in the central processing unit 4, it is possible to determine whether the bit pattern is adopted in the data communication system including the transmission line T to which the attached device ADA is connected. It is possible to estimate the communication agreement.

Then, in order to enable the large-scale integrated circuit 3 to operate according to the estimated communication protocol, the central processing unit 4 transmits the following information to the large-scale integrated circuit 3 for communication via the data bus 9. Data is provided for initializing the operating conditions to conform to the estimated communication protocol.

Thereby, the large-scale integrated circuit 3 for communication in the attached device ADA cooperates with the information storage device 5,
When serial data is supplied from the host computer HC to the attached device ADA in accordance with the communication protocol adopted between the host computer HC and the terminal device TA, it is transmitted via the bus 10 and the interface 1. Terminal equipment TA via line T
Serial data is transmitted from the terminal device TA to the attached device ADA in accordance with the communication protocol adopted between the host computer HC and the terminal device TA.
, it can be transmitted to the host computer HC via the bus 11 and the interface 2 over the transmission line T.

(Effects of the Invention) As is clear from the above detailed explanation, the present invention provides an accessory that is used by being connected to the transmission line T connected to the terminal device TA on which data communication based on the start-stop synchronization method is to be performed. The transmission line T to which the attached device ADA is connected is used as an automatic setting method for the conditions that enable data communication of the device ADA.
First, as data following the start bit, the first data in which the least significant bit is "1" is transmitted, and then as the second data, the number of "1" bits in the first data is transmitted. If the number is odd, the number of "1" bits is an even number, and if the number of "1" bits in the first data is even, the number of "1" bits is an odd number. In the means for transmitting data following the start bit and the above-mentioned accessory device ADA,
means for measuring the time length of a start bit transmitted prior to the first data transmitted to the transmission line T to determine the baud rate and sampling timing for data readout; Depending on the manner in which parity bits are added to the first data and second data transmitted to T, the type of parity check method adopted in the data communication system including the transmission line T can be determined. Comparing means for determining, a plurality of bit patterns prepared in advance, and bit patterns in the first information signal including the first data and the second information signal including the second data, A means for estimating the communication protocol adopted in the data communication system including the transmission line T, and an accessory device for enabling the attached device ADA to operate in accordance with the estimated communication protocol. By providing a means for setting operating conditions for ADA, even if there are various communication rules applied to data transmission between the host computer HC and the terminal device TA, it is possible to simply set the transmission line to which the attached device ADA should be connected. the first predetermined for T;
Transmits a second information signal to the attached device
Just allow the ADA to be supplied with the attached equipment
Since the operating mode of the ADA is automatically set to correspond to the specific communication protocol applied to data transmission on the transmission line T, the method of the present invention can satisfactorily solve all the problems of the conventional method.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing a schematic configuration of an embodiment of a method for automatically setting conditions that enable data communication of attached devices according to the present invention, and Fig. 2 shows an automatic setting of conditions that enable data communication of attached devices. FIG. 3 is a block diagram showing an example of the structure of the attached equipment. HC...host computer, TA...terminal device, T...data transmission line, ADA...attached equipment, 1...interface with terminal device TA,
2...Interface with host computer HC, 3...Large-scale integrated circuit for communication, 4...Central processing unit, 5...Information signal storage device (for example, using a magnetic recording medium such as a floppy disk) magnetic recording/reproducing device), 6...
...Input port, 7... Read only memory (ROM), 8... Random access memory (RAM), 9 to 11... Data bus.

Claims (1)

[Claims] 1. A method for automatically setting conditions to enable data communication of an accessory device used by connecting to a transmission line connected to a terminal device to which data communication is to be performed using the start-stop synchronization method, where the accessory device is The first data whose least significant bit is "1" is transmitted as the data following the start bit to the connected transmission line, and then the "1" in the first data described above is transmitted as the second data. ” is an odd number, the number of “1” bits is an even number, and if the number of “1” bits in the first data is even, the number of “1” bits is an even number. means for transmitting data whose number is an odd number following a start bit, and the above-mentioned accessory device, measuring the length of time of the start bit transmitted prior to the first data transmitted to the above-mentioned transmission line. The transmission line is controlled by means for determining the baud rate and sampling timing for data readout, and by adding parity bits to the first data and second data transmitted to the transmission line. means for determining the type of parity check adopted in the data communication system, a plurality of bit patterns prepared in advance, a first information signal including the first data; means for estimating a communication protocol adopted in a data communication system including a transmission line by comparing bit patterns in a second information signal including second data; An automatic setting method of conditions for enabling data communication of an accessory device, comprising means for setting operating conditions in the accessory device so that the accessory device can operate in accordance with communication regulations.