JPH10222445A - Method, system for bidirectional data communication and recording medium recording control program for performing bidirectional data communication - Google Patents

Abstract

PROBLEM TO BE SOLVED: To quickly report the change of specified information concerning a peripheral device to a host computer corresponding to that change in bidirectional communication at a centronics interface. SOLUTION: A status command is set to a printer so as to transmit the specified information concerning the printer of peripheral device at a printer driver on the side of host computer to the host side through bidirectional communication (302) and when there is any change in that set specified information at the printer, the change of specified information is reported to the host side by making a Fault signal active. When the level change of Fault signal is detected at the printer driver (304), negotiation is performed so as to quickly transmit information to the printer (305) and after it is confirmed whether the status command is set or not corresponding to that negotiation at the printer, status information is transmitted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-way data communication method, a two-way data communication system, and a recording medium on which a control program for performing two-way data communication is recorded, and more particularly to a peripheral device using a centronics interface. In a host device such as a connected host computer, bidirectional communication allows specific information on a peripheral device to be transmitted to the host device through bidirectional communication, and any change in the information to be immediately notified to the host device. The present invention relates to a data communication method, a two-way data communication system, and a recording medium on which a control program for performing two-way data communication is recorded.

[0002]

2. Description of the Related Art In recent years, a parallel port interface bidirectional communication defined in the IEEE 1284 standard standardized by IEEE (American Electrical and Electronic Engineers Association) has been used to determine the current operating state and error state of peripheral devices using Centronics. It is possible to notify a host computer via an interface, thereby producing a peripheral device such as a printing device which is easy for the user to use.

The two-way communication method defined in the IEEE1284 standard includes a nibble mode and an ECP (Extend).
ed Capabilities Port) mode, EPP (Enhanced Para
relPort) mode. The nibble mode is provided for performing bidirectional data transfer with existing models. Data is transferred from a printer to a personal computer (personal computer) in 4-bit units using four Centronics status signals. Centronics, which is currently used as an interface between a personal computer and a printer, has a maximum data transfer rate of 100 to 150 kbytes / sec. In the ECP mode and the EPP mode, the data transfer rate is improved in addition to the two-way communication. Maximum data transfer rate is EC
The P mode is 2 Mbytes / sec, and the EPP mode is 8 Mbytes / sec. Further, the ECP mode has a data compression function performed by hardware. In the ECP mode, only one peripheral device can be connected, whereas in the EPP mode, a maximum of seven peripheral devices (excluding the personal computer) can be daisy-chain connected.

However, in order to use the ECP mode or the EPP mode, it is necessary to connect a special parallel I / O (input / output) port capable of performing bidirectional data communication. When the parallel I / O port is used, communication in the ECP mode or the EPP mode cannot be performed, and bidirectional communication is often performed in the nibble mode.

When there is data to be transmitted from a peripheral device, in the ECP mode, nPeriphRequest (nFault)
By making the signal active (Low: low level), it is possible to immediately notify the host computer of a change in the state of the peripheral device.

However, when bidirectional communication is performed using the nibble mode, the mode always returns to the compatibility mode (compatible mode) when data is transmitted from the host computer. In order to receive the state even if it changes, the polling in the nibble mode is performed at intervals of, for example, every two seconds by a periodic timer or the like to confirm the state of the change of the peripheral device.

[0007]

In the conventional example as described above, in an I / O port that can support only the nibble mode, when the state of the peripheral device changes during idle in the normal compatibility mode, the maximum is about Due to the time loss of two seconds, it was not possible to immediately notify the host computer of a change in specific information in the peripheral device.

In order to check the status of peripheral devices, a periodic handler (one of basic programs for controlling input / output devices) is used.
Negotiations (negotiating) with the peripheral device are performed at intervals of every two seconds, for example, and the information data of the peripheral device is received in the nibble mode. Performance in terms of speed (performance) was reduced.

Therefore, according to the present invention, in bidirectional communication using a combination of a compatibility mode and a nibble mode in the above-described conventional Centronics interface, the information has changed in response to a change in specific information on peripheral devices. Data communication method, a two-way data communication system, and a recording medium on which a control program for performing two-way data communication is recorded, which can immediately notify a host device (for example, a host computer) of the fact. Aim.

[0010]

According to one aspect of the present invention, there is provided a bidirectional data communication method in which a host device and a peripheral device are connected by a Centronics interface. A first step of setting the peripheral device to transmit specific information on the peripheral device to the host device by two-way communication; and a setting set by the host device on the peripheral device side. When there is a change in the information, a second step of notifying the host device of the change of the specific information by activating a specific control signal, and on the host device side,
A third step of detecting a level change of the specific control signal and negotiating to immediately transmit information to the peripheral device.

Here, in the first step, a status command relating to specific information on the state of the peripheral device is created, and the specific command for setting the status command and the specific control signal to active is set. It can be set to the peripheral device by the Centronics interface.

Further, in the peripheral device, the third device
In response to the interruption of the negotiation by the step of, whether or not the status command is set, if the status command is set,
The method may include a fourth step of transmitting the status command information and, after transmitting all the latest status command information, setting the specific control signal to an inactive state.

According to a fourth aspect of the present invention, there is provided a bidirectional data communication method in which a host device and a peripheral device are connected by a Centronics interface, wherein the peripheral device always responds when a negotiation is performed in the host device. As described above, necessary information is selected from status commands for specific information relating to the state of the peripheral device, set as a status command, and when there is a change in the status command information, the status command information is changed. Setting a specific control signal setting command to an enabled state so as to set a specific control signal used for notifying a change to be active; and determining whether the status command is set in the peripheral device. The status command is set. If the status command has been updated, the status command is updated, and then, when the specific control signal is active and the setting information of the status command is changed, the specific control signal is activated. Thus, a step of notifying the host device that a part or all of the set status command has changed, and, when the host device detects that the specific control signal becomes active, the peripheral device Performing negotiation with the peripheral device and receiving status information such as the state of the peripheral device from the peripheral device by bidirectional communication; and, in the peripheral device, determining whether the status command has been set in response to the negotiation interrupt. Check that the status command is set Characterized by a step of the particular control signal to the inactive state After sending the status information, and transmits all the latest status command information.

The invention according to claim 5 is a bidirectional data communication method in which a host device and the peripheral device are connected by a Centronics interface, and bidirectional data communication is performed by a combination of a compatibility mode and a nibble mode. In the host device, at startup,
Transmitting a status command of the operation state in a compatibility mode to set a specific control signal setting command to an enable state in order to know the operation state of the peripheral device; and analyzing the status command in the peripheral device. Creating transmission status data and activating a specific control signal; and performing, in the host device, a negotiation with the peripheral device in response to the specific control signal being activated, and setting a nibble mode. Receiving a status of "not operating" and then terminating; returning the compatibility control mode to a normal state in the peripheral device; and returning the specific control signal to a normal state in the host device. Compile data to device Transmitting in an availability mode, and in the peripheral device, when a change occurs in an operation state, activating a specific control signal; and in the host device, receiving the specific control signal being activated. And negotiating again to receive information on the state of the peripheral device.

Here, it is assumed that the command of the operation state status includes an operation state such as feeding, printing, discharging, and not operating, or information such as error information. Can be. The error information includes, for example, a paper feed error.

According to a seventh aspect of the present invention, in the bidirectional data communication system in which a host device and a peripheral device are connected by a Centronics interface, the host device transmits specific information on the peripheral device by the bidirectional communication. Means for setting a status command for the peripheral device by the Centronics interface to transmit to the host device, and negotiation to detect a level change of a specific control signal and immediately transmit information to the peripheral device. Means to do,
The peripheral device notifies the host device of a change in the specific information by activating the specific control signal when specific information set by the status command from the host device changes. It is characterized by having means.

Here, the peripheral device checks whether or not the status command has been set in response to an interruption of the negotiation by the host device.
When the status command is set, a means for transmitting status command information to the host device and inactivating the specific control signal when all the latest status command information has been transmitted can be provided.

Further, the host device may include an analyzing unit that receives the status command information from the peripheral device and analyzes the content of the status command information.

Further, the host device may include a display unit capable of displaying a result analyzed by the analysis unit using a graphic.

Further, the peripheral device may include an arithmetic control unit capable of analyzing and determining the status command.

Further, the peripheral device may include a storage unit having a program and a work area for executing a control command of the arithmetic control unit.

Further, according to a thirteenth aspect of the present invention, there is provided a recording medium storing a control program for performing bidirectional data communication in a system in which a host device and a peripheral device are connected by a Centronics interface. Causes the computer of the host device to select necessary information from status commands corresponding to specific information relating to the state of the peripheral device and set it as a status command so that the peripheral device always responds when a negotiation is performed. A state in which a specific control signal setting command can be used to activate a specific control signal used for notifying a change in the information of the status command when the information of the status command changes. And the specific control signal is By detecting from becoming revertive, to perform the negotiation with respect to the peripheral device, and characterized in that receive status information such as the state of the peripheral device by way communication from the peripheral device after said negotiation.

Here, the control program causes the computer of the peripheral device to determine whether or not the status command has been set, and, if the status command has been set, to update the status command. Next, the specific control signal is active,
And when a change is found in the setting information of the status command, by activating the specific control signal, the host device is informed that a change has been made in part or all of the set status command. Inform, in response to the negotiation interrupt, confirm whether the status command is set,
When the status command is set, the status information can be transmitted, and when all the latest status command information has been transmitted, the specific control signal can be set to the inactive state.

[0024]

Embodiments of the present invention will be described below in detail with reference to the drawings.

(First Embodiment) FIG. 1 shows an apparatus configuration of an embodiment in which the present invention is applied to communication between a host computer (host device) and an ink jet printer which is a peripheral device. The devices that can use the bidirectional data communication method of the present invention include various peripheral devices such as an image scanner device (image reading device) and a computer in addition to various printer devices such as the ink jet printer of the present embodiment. Can be considered.

Further, the present invention may be applied to a system constituted by a plurality of devices or to an apparatus constituted by a single device. Needless to say, the present invention can also be applied to a case where the present invention is achieved by supplying a system or an apparatus with a program for implementing the present invention recorded on a recording medium such as a magnetic disk.

In FIG. 1, reference numeral 101 denotes a host computer (host device) such as a personal computer.
A printer driver 10 in the form of software (program) for controlling the inkjet printer 104 in the same housing.
Contains 2. The printer driver 102 is connected to an inkjet printer 104 via a parallel I / O port 103 of the host computer 101 and a Centronics interface cable 105.
The parallel I / O port 103 is a printer driver 102
Is converted into a level change (low level / high level) of each signal line of the cable 105 to exchange information with the ink jet printer 104.

The interior of the ink jet printer 104 is configured as shown in FIG. 2, and a CPU (Central Processing Unit) 201 controls the operation of the printer and various processes. Reference numeral 202 denotes a parallel I / O port which receives print data and setting commands from the host computer 101, and receives printer data by bidirectional communication.
04 is transmitted to the host computer 101. 2
03 is a ROM (read only memory),
01 stores data such as a control program to be executed. Reference numeral 204 denotes a RAM (random access memory) which is used when the CPU 201 executes a control process.
Stores transmission information for information set in the work area or host computer used for various calculations. Reference numeral 205 denotes a printing apparatus including a scanning control unit such as an inkjet head and various motor control drivers and a print control unit, which receives a control signal supplied from the CPU 201 and performs printing on a print medium according to the signal. .

FIG. 3 is a flowchart showing an operation procedure for obtaining status information of the printer driver 102 in FIG.

FIG. 4 is a flowchart showing the operation of the printer 1 shown in FIG.
4 shows a procedure of a process performed by a timer interrupt inside 04. In this embodiment, this process is performed by a timer interrupt for the sake of explanation. However, the same effect can be obtained by performing an event interrupt process for a change in a set command.

The flowchart of FIG. 5 shows the procedure of the process of the printer 104 when the negotiation interrupt is activated from the Centroport by the process of the printer driver 102 of FIG.

Next, the operation of the ink jet printer system according to the embodiment of the present invention will be described with reference to FIGS.
This will be described in detail with reference to the flowchart of FIG.

As shown in FIG. 3, the printer driver 10
2 is activated (step 301), first, necessary information is selected from status commands for specific information relating to the status of the printer, which are already negotiated with the printer 104, and the parallel I / O is selected. Centronics interface 105 from O port 103
To the printer 104 (step 302).
Thus, the setting is made so that the printer 104 always responds when the negotiation is performed with the printer 104.

In this embodiment, the command is set by the printer driver 102.
This can be achieved even when a command to be always transmitted to the device 4 is set in advance.

Next, when there is a change in the status command information, the printer driver 102 sends a specific control signal used to notify the change in the status command information, for example, a Fault signal (fault signal). Is set to be active (LOW: low level), a fault signal setting command is set to a usable state (enable) for the printer 104 through the parallel I / O port 103 (step 303).

The printer 104 interprets the status command and the fault signal setting command, and creates a command to respond to the printer driver 102 based on the status of the printer 104 corresponding to the command. That is,
As shown in FIG. 4, when a timer interrupt occurs (step 401), the printer 104 determines whether or not a status command has been set (step 402). The operation is interrupted (step 408).

If the status command has been set, the status command is updated (step 403). Next, the Fault signal is enabled (Enabl
e) is available, and the setting information of the status command is changed (steps 404 and 40).
5) By activating the Fault signal,
The host computer 101 is notified that part or all of the set status command has changed (step 406), and exits from the interrupt processing (step 408).

Otherwise, that is, when the Fault signal is disabled (Disable) or when the setting information of the status command does not change (Steps 404 and 405), the Fault signal is normally output. The use state is kept as it is (step 407), and the process exits from the interrupt processing (step 408).

When the printer driver 102 has set the fault signal setting command to the usable state (enable), the printer driver 102 sets the fault signal as shown in FIG.
When it is detected that the signal becomes active (low level) (step 304), negotiation is performed with the printer 104, and status information such as the status of the printer is received from the printer 104 by bidirectional communication (step 305).

Thereafter, after transmitting all information from the host to the printer 104, termination (end processing) is performed by the printer driver 102, and when the mode returns to the compatibility mode again (step 306), the printer 1
04 returns the Fault signal to a normal use state.

Further, as shown in FIG.
In, when a negotiation interrupt occurs (step 501), it is confirmed whether or not the status command is set (step 502). If the status command is not set, IEEE 1284
As specified in the standard, "Data Not Avail
"able state", that is, a data transmission disabled state (step 506), and the process exits (step 507).

On the other hand, if the status command is set, the printer 104 transmits the status information to the host computer 101 (step 503), and after all the commands have been transmitted through all the protocols according to the standard specification. (Step 504) When returning to the compatibility mode, the printer 104 is not in the normal Fault state (error state) but is in the printer driver 102.
When all of the latest status command information has been transmitted to the
H: high level) (step 505). Fa
The normal state of the ult signal depends on the emulation mode, but in most cases, it becomes active (LOW: low level) when an error occurs.

The printer 104 transmits status information in response to the negotiation from the printer driver 102 regardless of the setting state of the Fault signal setting command.

If there is any inconvenience in the above protocol, the printer 104 sets the Fault signal to the same state as when the negotiation occurred, and exits the processing (step 507).

Even if the printer driver 102 returns to the compatibility mode (step 306), if the Fault signal remains active (LOW: low level) (step 307), it is determined that an error state has occurred. If necessary, the printer 104 can negotiate periodically with the printer 104 using a cyclic handler or the like to check the status of the printer 104 (step 308).

After returning to the compatibility mode (step 306), the printer driver 102 sets Fa
ult signal is inactive (HIGH: high level)
If so, the process returns to step 304 described above.

In the flowchart of FIG. 3, the process can be interrupted in all states. However, in order to prevent a malfunction when the emulation mode is changed to another, the printer driver 102 terminates the operation. Must always disable (disable) the Fault signal setting command.

If the fault signal setting command is not set to a usable state, the operation of the fault signal follows the normal emulation mode.

The status command of this embodiment includes:
For example, various information such as error information, printed information of the printer, mounted head information, and printer operation information can be transmitted.

[0050]

EXAMPLES Examples of the present invention will be described with reference to more specific examples.

First, when the printer driver 102 is activated, first, in order to know the operation state of the printer 104,
An operation status command is transmitted to the printer 104 in the compatibility mode. Similarly, the printer driver 102 sets the Fault signal setting command to the enable state. Here, it is assumed that the command of the operation state status includes four pieces of information indicating that the sheet is being fed, printing, discharging, and not operating (FIG. 3).
301-303).

The printer 104 analyzes the status command (operation status command) and creates transmission data. At present, the printer 10 is not operating.
4 creates a status of "not working" and Fa
Since the "ult" signal setting command is enabled, the "Fault" signal is activated (401 in FIG. 4).
406).

In response to the fact that the Fault signal has become active, the printer driver 102 negotiates with the printer 104 and receives a status “not operating” from the printer 104 in the nibble mode or the like. Subsequently, when termination is performed by the printer driver 102 and the mode returns to the compatibility mode (304 to 306 in FIG. 3), the printer 104
The ult signal is returned to a normal state (404 and 40 in FIG. 4).
7).

Next, print data is transmitted from the printer driver 102 to the printer 104 in the compatibility mode for printing on the printer 104. Upon receiving the print data, the printer 104 analyzes the print data and starts printing. At this time, if the sheet is fed, a change occurs in the operation state monitored by the periodic handler or the like, so that the printer 104 activates the Fault signal again (405 and 406 in FIG. 4).

The printer driver 102 receives the fact that the Fault signal has become active, negotiates again, and can receive the information of "paper feeding" as in the previous case (307 and 308 in FIG. 3). Printer 10
Then, the state of No. 4 is during printing and discharging, and becomes "not operating" again.

As described above, since the printer driver 102 knows the status of the printer 104 while sending print data, the printer driver 102 displays the status of the printer 104 on a display screen (not shown) of the host computer 101 using, for example, graphics. And the printer 10
4 can be provided to the user in a manner that is easily understood by the user.

Further, if error information is set in advance in the status command, when an error condition occurs in the printer 104, the printer driver 102 can display a countermeasure for the error on the display screen.
As a result, even a user who does not know how to deal with a printer error can immediately understand the details of the error and take appropriate action.

[0058]

As described above, according to the present invention,
In bidirectional communication between the host device and the peripheral device, a specific control signal (for example, Fau
lt signal) makes it possible to immediately notify the host device and the user of a change in the state of the peripheral device, and to increase the number of times of operation compared to the conventional inquiry of information to the peripheral device by the periodic timer. The load on the host device is reduced,
High performance two-way communication can be realized.

Further, according to the present invention, it is possible to immediately know the information of the peripheral device, so that it is possible to provide more accurate and timely detailed information to the host device.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an example of a system configuration in which the present invention is applied to bidirectional communication between a host computer and an inkjet printer.

FIG. 2 is a block diagram showing an internal circuit configuration of the inkjet printer of FIG.

FIG. 3 is a flowchart showing a control operation relating to acquisition of status information of the printer driver according to the embodiment of the present invention in FIG. 1;

FIG. 4 is a flowchart showing a timer interrupt control processing operation inside the printer according to the embodiment of the present invention in FIG. 1;

FIG. 5 is a flowchart showing a processing operation of controlling the printer when the negotiation interrupt or the negotiation is started in the embodiment of the present invention in FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 101 Host computer 102 Printer driver 103 Parallel I / O port 104 Inkjet printer 105 Centronics cable 201 CPU 202 I / O port 203 ROM 204 RAM 205 Printing device

Claims (14)

[Claims] 1. A bidirectional data communication method in which a host device and a peripheral device are connected by a Centronics interface, wherein the host device transmits specific information on the peripheral device to the host device by bidirectional communication. A first step of setting for the peripheral device so that the specific information set by the host device changes on the peripheral device side by activating a specific control signal. A second step of notifying the change of the specific information to the host device; and negotiating that the host device detects a level change of the specific control signal and immediately transmits the information to the peripheral device. A two-way data communication method. 2. The method according to claim 1, wherein the first step is to generate a status command relating to specific information on a state of the peripheral device, and to execute the specific command for setting the status command and the specific control signal to be active. The two-way data communication method according to claim 1, wherein the setting is made to a peripheral device by an interface. 3. In the peripheral device, in response to an interruption of the negotiation in the third step,
Check whether the status command is set, if the status command is set, send status command information, and after transmitting all the latest status command information, the specific control signal to the inactive state 3. The two-way data communication method according to claim 2, further comprising a fourth step of performing the following. 4. A two-way data communication method in which a host device and a peripheral device are connected by a Centronics interface, wherein the host device always responds when a negotiation is performed in the host device. Required information is selected from status commands for specific information relating to the state of the device, set as status commands, and when there is a change in the status command information, the change in the status command information is notified. Setting a specific control signal setting command to a usable state in order to set a specific control signal to be used to be activated, and in the peripheral device, determine whether the status command is set, If the status command has been set Processes for updating the theta scan command, then the specific control signal is active, and when a change in the setting information of the status command is observed, by activating the specific control signal,
Notifying the host device that part or all of the set status command has changed; and, in the host device, negotiation with the peripheral device upon detecting that the specific control signal becomes active. And receiving status information such as the state of the peripheral device from the peripheral device by bidirectional communication.In the peripheral device, confirm whether the status command is set in response to the negotiation interrupt. Transmitting the status information when the status command is set, and inactivating the specific control signal when all the latest status command information is transmitted. Communication method. 5. A bidirectional data communication method in which a host device and the peripheral device are connected by a Centronics interface and perform bidirectional data communication by a combination of a compatibility mode and a nibble mode. Sometimes, in order to know the operation state of the peripheral device, transmitting a status command of the operation state to the compatibility mode, and setting a specific control signal setting command to an enable state, and in the peripheral device, Analyzing the command, creating transmission status data, and activating a specific control signal; and, in the host device, receiving negotiation of the peripheral device in response to the specific control signal being activated. By nibble mode Receiving a status of "not operating" and then terminating; returning the compatibility control mode to the specific control signal in the peripheral device; returning the specific control signal to a normal state; Transmitting data to the peripheral device in a compatibility mode; activating a specific control signal when an operation state changes in the peripheral device; and activating the specific control signal in the host device. Receiving the information on the state of the peripheral device. 6. The operation status command includes an operation status such as feeding, printing, discharging, and not operating, or information such as error information. The two-way data communication method according to claim 5, wherein: 7. A bidirectional data communication system in which a host device and a peripheral device are connected by a Centronics interface, wherein the host device transmits specific information on the peripheral device to the host device by bidirectional communication. A means for setting a status command for the peripheral device by the Centronics interface, and a means for detecting a level change of a specific control signal and negotiating to immediately transmit information to the peripheral device, The peripheral device notifies the host device of a change in the specific information by activating the specific control signal when specific information set by the status command from the host device changes. Interactive means characterized by having means Communication system. 8. The peripheral device checks whether or not the status command is set in response to an interruption of the negotiation by the host device. If the status command is set, the peripheral device transmits status command information. 8. The two-way data communication system according to claim 7, further comprising: means for setting the specific control signal to an inactive state when transmitting the latest status command information to the host device and transmitting all the latest status command information. 9. The bi-directional device according to claim 8, wherein the host device includes an analyzing unit that receives the status command information from the peripheral device and analyzes the content of the status command information. Data communication system. 10. The host device according to claim 9, further comprising a display unit capable of displaying a result analyzed by the analysis unit using a graphic.
A two-way data communication system according to claim 1. 11. The two-way data communication system according to claim 7, wherein said peripheral device includes an arithmetic control unit capable of analyzing and determining said status command. 12. The two-way data communication system according to claim 11, wherein said peripheral device includes a storage unit having a program and a work area for executing a control command of said arithmetic control unit. 13. A recording medium recording a control program for performing bidirectional data communication in a system in which a host device and a peripheral device are connected by a Centronics interface, wherein the control program is stored in a computer of the host device. In order to ensure that the peripheral device responds when a negotiation is performed, necessary information is selected from status commands for specific information relating to the state of the peripheral device and set as a status command. When there is a change, a specific control signal setting command is set to a usable state to set a specific control signal used for notifying a change in information of the status command to be active, and the specific control is performed. Signal is activated Let me
A control program for performing bidirectional data communication, characterized by causing the peripheral device to perform negotiation, and receiving status information such as the state of the peripheral device from the peripheral device by bidirectional communication after the negotiation. Recording medium on which is recorded. 14. The control program causes a computer of the peripheral device to determine whether or not the status command has been set, and if the status command has been set, performs a process of updating the status command. In the case where the specific control signal is active and the setting information of the status command changes, by activating the specific control signal, a part or all of the set status command is set. To the host device, and in response to the interruption of the negotiation, confirm whether or not the status command is set, and when the status command is set, transmit the status information. And send all the latest status command information. Recording medium according to claim 13, characterized in that to the control signal to the inactive state.