JPH05244216A - Transfer mode setting system - Google Patents

Abstract

PURPOSE:To set a transmission mode automatically by sending a transfer mode initializing signal from a transmission side to a reception side, initializing the transfer mode on the transmission side and the reception side so as to make the modes coincident with each other, and thereby setting the transfer mode. CONSTITUTION:The transfer mode initializing signal 5 is sent to the input output device 2 of the reception side from a computer 1 at the transmission side. Upon the receipt of the signal 5, the reception side initializes the transfer mode and sends a completion code 4 to the transmission side when the initializing is finished. Then the combination 3 of transfer mode setting characters to set the content of the transfer mode corresponding to the transfer mode is sent from the transmission side, the reception side decodes it to set the transfer mode. Thus, it is not required to make the transfer modes of the transmission side and the reception side coincident with each other, thereby setting the transfer mode automatically. Furthermore, even when the transfer mode is revised by ON/OFF of a power supply on the transmission side and the reception side, etc., in the course of the transfer, the transfer mode is set again automatically.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer mode setting method for setting a transfer mode in a communication system in which communication between a transmitting side and a receiving side is asynchronous and serial.

[0002]

2. Description of the Related Art FIG. 5 shows, for example, JP-A-63-283336.
6 is a flowchart for explaining the operation of the conventional transfer mode setting method disclosed in Japanese Patent Publication No. In FIG. 5, the transfer baud rates of the transmitting side and the receiving side are set to be the same before setting the transfer mode between the transmitting side and the receiving side, and the transmitting side specifies a transfer mode at a predetermined time from the transmitting side at the start of communication. The character is transmitted (step 41). The receiver is
The start bit in the character sent from the transmitting side is detected (step 42), the data bit of the character is checked, and it is determined whether or not the character code is "H" (step 43). If it is ", the data bit length is counted (step 44) and the code of the parity bit and the stop bit is judged (step 45). Next, the receiving side judges whether or not the judged code is in the built-in ROM (step 46), and if there is, sets the contents of the transfer mode such as the data bit length, parity format, stop bit length, etc. (step 47). After that, the receiving side responds to the transmitting side with a signal indicating that reception is possible (step 4).
8), execute data communication with the sender (step 4)
9).

[0003]

Since the conventional transfer mode setting method is configured as described above, it is necessary to set the transfer baud rates of the transmitting side and the receiving side to be the same before setting the transfer mode. Also, after changing the transfer mode setting, if the setting on the sending side is returned to the default by turning the power off and then on, the transfer mode on the sending side and receiving side will not match and communication will be impossible, and work on setting the transfer mode from the beginning There was a problem such as having to go and establish communication.

The present invention has been made in order to solve the above problems, and eliminates the need for preliminarily matching the transfer modes of the transmitting side and the receiving side so that the transfer modes can be set automatically. It is also an object of the present invention to provide a transfer mode setting method capable of automatically setting the transfer mode again even if the transfer mode is changed due to power-off or power-on of the transmitting side or the receiving side during transfer. .

[0005]

The transfer mode setting method according to the invention of claim 1 is such that the transmission side (computer 1) sends a transfer mode initialization signal to the reception side (input / output device 2). And the transfer mode of the receiving side are initialized and matched, and then the sending side sends a combination of transfer mode setting characters for setting the contents of the transfer mode to the receiving side, and the receiving side transfers the above-mentioned transfer. The transfer mode is set by decoding the combination of mode setting characters.

In the transfer mode setting method according to the second aspect of the present invention, the transfer mode initialization signal is transmitted from the transmission side (computer 1) to the reception side (input / output device 2) so that the transfer modes of the transmission side and the reception side are transferred. After initializing and matching, the transmission side sends a transfer mode setting command and then transfer mode setting data for setting the contents of the transfer mode such as data bit length and transfer speed, and the receiving side sends those data. By decoding, the transfer mode is set.

[0007]

In the invention of claim 1, the transmitting side (computer 1)
When the transfer mode initialization signal is sent to the receiving side (input / output device 2) from the transmitting side, the transfer modes of the transmitting side and the receiving side are initialized and coincide with each other, and then the combination of the transfer mode setting characters from the transmitting side is received by the receiving side. Is sent to the receiving side, and the receiving side decodes the sent combination of characters and sets the transfer mode.

In the invention of claim 2, after the transfer mode is initialized and coincides with each other in the same manner as described above, the transfer mode setting command and then the transfer mode setting data are transmitted from the transmitting side (computer 1) and the receiving side (input). The output device 2) decodes those data and sets the transfer mode.

[0009]

EXAMPLES Example 1. FIG. 1 is a block diagram showing a main configuration of a communication system adopting a transfer mode setting method according to an embodiment of the present invention. In FIG. 1, 1 is a computer on the transmitting side, 2 is an input / output device on the receiving side, 3 is data transmitted from the computer 1 to the input / output device 2, and 4 is data received by the computer 1 from the input / output device 2. Is a transfer mode initialization signal (DTR signal) for the computer 1 to synchronize with the input / output device 2.

Next, the operation from initialization to mode setting in this embodiment will be described with reference to the flow chart of FIG. First, a transfer mode initialization signal (DTR signal) 5 is sent from the transmitting side (computer 1) (step 21), and the receiving side (input / output device 2) receives the DTR signal 5 (step 22). The transfer mode (transfer rate, data length, parity bit, stop bit, etc.) on the receiving side is initialized so that both are in the same transfer mode (step 23).

Next, when the initialization of the transfer mode is completed, the receiving side sends a completion code to the transmitting side (step 24) and waits for a command from the transmitting side. After the sender receives the completion code from the receiver (step 2
5) A command for setting the transfer mode, that is, a transfer mode setting command is sent (step 26), and then transfer mode setting data for setting the contents of the transfer mode is sent (step 27). The transfer mode setting command consists of data of a predetermined character code, and the transfer mode setting data consists of, for example, 1 byte of data. In steps 26 and 27, the combination of the transfer mode setting command and the transfer mode setting data, that is, the combination of the transfer mode setting characters is sent from the transmitting side to the receiving side.

The transfer mode setting data consists of 1-byte data as shown in FIG. 3. The 0th bit is a busy control selection bit, the 1st bit is a character length selection bit, and the 2nd bit is a parity selection bit. A parity bit selection bit is set in the third bit, a stop bit selection bit is set in the fourth bit, and a transfer speed bit is set in the fifth to seventh bits. The transfer rate is 5, for example, as shown in FIG.
When the predetermined bits are set in the 6th and 7th bits, the transfer rate is designated.

Returning to FIG. 2, after step 27, the receiving side decodes the transfer mode setting data following the transfer mode setting command sent from the transmitting side to transfer rate, data length, parity bit, and stop. It is possible to execute data communication between the transmitting side and the receiving side by executing various settings such as bits (step 28) and sending (response) a reception enable code indicating a data receivable state to the transmitting side (step 29). (Step 30).

As described above, according to the above embodiment,
By sending a transfer mode initialization signal from the transmission side, the transfer mode on the reception side can be automatically matched with the transfer mode on the transmission side without using hardware means such as a DIP switch, and the power on the transmission side is turned off. , Even if the default mode is turned on, the transfer mode setting signal is sent again from the transmission side to synchronize the transfer modes of the transmission side and the reception side. Also, the transfer mode setting contents can be specified by the 1-byte transfer mode setting data following the transfer mode setting command.

Example 2. In the above embodiment, the computer is arranged on the transmitting side and the input / output device is arranged on the receiving side. However, a computer may be arranged on both the transmitting side and the receiving side, or another communication device may be arranged.

[0016]

As described above, according to the present invention, by transmitting a transfer mode initialization signal from the transmitting side to the receiving side, the transfer modes of the transmitting side and the receiving side are initialized and matched, and then the transmitting side. The transfer mode setting character combination (transfer mode setting command and transfer mode setting data) is sent to the receiving side, and the receiving side decodes the combination of the transfer mode setting characters to set the transfer mode beforehand. It is not necessary to match the transfer mode of the sending side and the receiving side, the transfer mode can be set automatically, and
Even if the transfer mode is changed during the transfer due to power-off or power-on of the sender or the receiver, the receiver can be initialized and the transfer mode can be set automatically again. The effect of improvement is obtained.

[Brief description of drawings]

FIG. 1 is a block diagram showing a main configuration of a communication system adopting a transfer mode setting method according to an embodiment of the present invention.

FIG. 2 is a flowchart showing the operation of this embodiment.

FIG. 3 is a diagram showing the contents of transfer mode setting data in this embodiment.

FIG. 4 is a diagram showing a correspondence between transfer rate bits and transfer rates in the transfer mode setting data of FIG.

FIG. 5 is a flowchart showing the operation of a conventional transfer mode setting method.

[Explanation of symbols]

 1 computer (sending side) 2 input / output device (receiving side)

Claims (2)

[Claims] 1. In a communication system in which communication between a transmission side and a reception side is performed asynchronously and serially, a transfer mode initialization signal is sent from the transmission side to the reception side to initialize the transfer mode of the transmission side and the reception side. Then, the transmission side sends a combination of transfer mode setting characters corresponding to the transfer mode and sets the contents of the transfer mode to the receiving side, and the receiving side decodes the combination of the transfer mode setting characters. A transfer mode setting method characterized in that the transfer mode is set accordingly. 2. In a communication system in which communication between a transmission side and a reception side is performed asynchronously and serially, a transfer mode initialization signal is sent from the transmission side to the reception side to initialize the transfer mode of the transmission side and the reception side. After sending the transfer mode setting command, the sending side sends the transfer mode setting command, then sends the transfer mode setting data for setting the contents of the transfer mode such as the data bit length and transfer speed, and the receiving side sends those data. A transfer mode setting method characterized by setting a transfer mode by deciphering.