JPH06332811A - Display and control method - Google Patents

Abstract

(57) [Abstract] [Purpose] Allows the host computer to detect the status of the display. In a display having a command receiving means from a host computer and a status line control means for notifying a status of the display, a status line is controlled to an ON state or an OFF state by a command from the host computer. [Effect] The problem of data disappearance is eliminated by executing data transmission after the host computer detects a display state change by a command.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to displays and control methods.

[0002]

2. Description of the Related Art A conventional display receives data from a host computer by turning on a status line when it is in a receivable state. Further, when the reception becomes impossible for some reason, the state line is changed to the OFF state. Therefore, the host computer detects the status line of the display and executes data transmission to the display only when it is in the ON state.

[0003]

However, in the above-mentioned conventional technique, when the status line of the display is in the ON state and the data receiving means is abnormal, the host computer cannot confirm this status. Since the status line is in the ON state as it is, data transmission is executed, and as a result, the data disappears.

If the display is not connected to the host computer, or if the display is connected but the power is off, the host computer determines that the status line of the display is in the ON state. Similarly, there is a drawback that the data is lost.

The present invention has been made to solve the above drawbacks, and the data is transmitted by executing data transmission to the display after the host computer confirms that the display is operating normally by the command. The purpose is to prevent disappearance or to detect to the user that the host computer detects that the display is malfunctioning.

[0006]

SUMMARY OF THE INVENTION A display and control method according to the present invention comprises a status line control means for notifying a host computer of a status, a means for receiving a command or data from the host computer, and the status line according to the command. In a display having means for changing the ON state or the OFF state, after confirming that the display is operating normally on the host computer side, by executing data transmission to the display, reliable data transfer control can be performed. Is characterized by.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be described with reference to FIG.

The display 100 waits for a command or display data from the host computer 110. When the command receiving means 101 receives a command from the host computer 110, the command selecting means 102 executes command selection. In the command selecting means 102, the command is ON for the status line.
If it is determined that the command is a command, the state line ON command receiving unit 103 executes the state line ON command process, the state line ON setting unit 104 sets the state line to the ON state, and the state line control unit 107 sets the host. The state line connected to the computer 110 is controlled to the ON state. On the other hand, the command is the command selection means 1
If it is determined in step 02 that the command is a status line OFF command, the status line OFF receiving means 105 causes the status line OFF command.
After executing the command processing, the state line OFF setting means 10
The state line is set to the OFF state by 6, and the state line control means 107 controls the state line connected to the host computer 110 to the OFF state. When the display data transmitted from the host computer 110 is received by the data receiving means 108, the display processing is executed by the data display means 109.

Before the host computer 110 transmits data to the display 100, the state line ON command transmitting means 111 and the state line OFF command transmitting means 1 are transmitted.
The command prepared by 12 is used as the command transmitting means 113.
To the display 100 via. After that, when the state line of the display 100 is detected by the state line detecting unit 114 and it is determined that the display 100 is normal, the display data prepared by the display data setting unit 116 is displayed on the display unit via the data transmitting unit 117. Send to 100.

On the other hand, when the status line detection means 114 determines that the display 100 is abnormal, the abnormality message display means 115 informs the user that an abnormality has occurred.

A specific display process by software is shown in the flowchart of FIG. First, a process (step 200) for determining whether the device is in the receivable state is executed. If it is determined that the reception is not possible, the state line OFF control process (step 201) is executed, and the process returns to the first process. On the other hand, if it is in the receivable state,
After executing the state line ON control process (step 202), the process proceeds to the reception data waiting process (step 203). When it is confirmed that there is received data in the received data waiting process (step 203), the data receiving process (step 2)
04) is executed. If it is determined that the received data is the status line ON command (step 205), the status line O
The N control process (step 206) is executed. It is determined that the received data is a status line OFF command (step 2
07), the state line OFF control processing (step 20)
Execute 8). If it is determined that the received data is display data (step 209), data display processing (step 210) is executed.

The specific processing of the host computer by software is shown in the flowchart of FIG. First, it is confirmed that the status line of the display is ON (step 300). If the status line of the display is not ON, the process waits until the status line of the display is turned ON. On the other hand, if the status line of the display is ON, the status line OFF command transmission process (step 301) is executed. Due to the processing time on the display side, there may be a difference between the command transmission and the timing at which the status line of the display is actually turned on.
02), the status line of the display is OF
A confirmation process (step 303) of the F state is executed. Here, when it is confirmed that the status line of the display is in the OFF state, the status line ON command transmission processing (step 304) is executed. After the time waiting process (step 305) similar to the above, the confirmation process (step 306) that the status line of the display has been turned on is executed. Here, if it is confirmed that the status line of the display is turned on, the display data transmission process (step 307) is executed,
Normal termination.

On the other hand, the status line OFF confirmation processing (step 303) or the status line ON confirmation processing (step 3).
If the status line of the display does not change normally in 06), it is determined that an abnormality has occurred in the display, and the host computer executes error display processing (step 308) and terminates abnormally.

[0014]

As described above, according to the present invention, when the host computer transmits data to the display, the state of the display is detected by a command, and after confirming that it is operating normally, the data is transmitted. By doing so, reliable data communication became possible because of the problem of data disappearance. Further, there is an effect that the host computer can notify the user by an error message or the like even when an abnormality occurs in the display by the host computer monitoring the state of the display by a command.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a flowchart showing an embodiment of the display of the present invention.

FIG. 3 is a flowchart showing an embodiment of a host computer according to the prior art.

[Explanation of symbols]

 100 display 101 command receiving means 102 command selecting means 103 state line ON command receiving means 104 state line ON setting means 105 state line OFF command receiving means 106 state line OFF setting means 107 state line control means 108 data receiving means 109 data display means 110 Host computer 111 State line ON command transmitting means 112 State line OFF command transmitting means 113 Command transmitting means 114 State line detecting means 115 Abnormal message displaying means 116 Display data setting means 117 Data transmitting means

Claims (4)

[Claims] 1. A state line control means for notifying a host computer of a current state, a means for receiving a command from the host computer, and a means for turning on the state line by a command from the host computer. A display characterized by. 2. The display according to claim 1, wherein the status line is turned off by a command from a host computer.
A display having means for changing to an F state. 3. After confirming that the display is not in an error state by a status line ON command and a status line OFF command in a system in which a host computer and a display are connected by at least one or more data lines and at least one or more status lines. , A control method characterized by transmitting display data. 4. The system according to claim 3, wherein the state line O
A control method characterized by notifying the user of the occurrence of an error when it is confirmed by the N command or the status line OFF command that the connected display is abnormal.