JPH06119276A - Information processing system - Google Patents

Abstract

PURPOSE:To enable the transmission of a new control signal to be conducted by means of an existing control line placed between a host device and a peripheral device so as to grasp various states of the peripheral device. CONSTITUTION:A cable 13 consisting of a data line 21, paper error signal 25 or the like is connected between a personal computer (host device) 11 and a laser printer (peripheral device) 12. The personal computer 11 uses the paper error signal line 25 in many ways other than the paper error detection, sending the specific data to the data line 21. The laser printer 12 accepts this and sends the other control signals to the paper error signal line 25. The switching of the control signal is performed by changing the logic of the control signal starting the transmission en route and detecting the presence or absence of the change.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information processing system including a host device such as a personal computer and a word processor and peripheral devices such as a laser printer,
More specifically, the present invention relates to an information processing system characterized by transmitting signals from a peripheral device to a host device.

[0002]

2. Description of the Related Art FIG. 8 shows an example of an information processing system. This system comprises a personal computer 11, a laser printer 12, and a cable 13 connecting them. The cable 13 is used for transmitting print data and control signals,
Although not shown in this figure, the personal computer 11
And the laser printer 12 via interface circuits.

FIG. 9 shows the timing of transmission of data and control signals in such an information processing system. This is data and strobes, busy, with Centronics parallel interface,
This is well known as a handshake for each acknowledge control signal.

FIG. 1A shows the transfer of data to eight data lines. Personal computer 11
When the data transmission to the data line is confirmed, the strobe signal shown in (b) of the figure is set to the L (low) level. When it is determined that the strobe signal is at the L level on the laser printer 12 side, the busy signal shown in FIG. 9C is switched from the L level to the H (high) level, and the next data is sent from the personal computer 11 side. Try not to come. Then, in this state, the data appearing on the data line is processed. When the laser printer 12 finishes processing the data and is ready to receive the next data, the acknowledge signal is once set to the L level and then returned to the H level as shown in FIG. Set to level.

By the way, the laser printer 12 cannot continue printing when a jam (paper jam) occurs or the paper runs out. Therefore, a control line for notifying the personal computer 11 of such a situation is arranged in the cable 13. When this control line is switched from the L level to the H level, for example, the personal computer 11 recognizes that a trouble has occurred on the laser printer 12 side and stops the subsequent data transmission.

[0006]

As described above, in the conventional information processing system, when the host device such as the personal computer 11 sends the data, the peripheral device such as the laser printer 12 receives the data. It was equipped with a means to inform them. However, even if, for example, the host device sends out a font for printing as data and requests its storage, there is no transmission of a control signal indicating that the storage has been performed reliably,
The host device side could not accurately grasp the state of the peripheral device.

Of course, such a problem can theoretically be solved by preparing various control lines such as a dedicated control line for notifying a trouble relating to the paper. However, it is actually impossible to provide a large number of control lines to provide control lines for confirming that the peripheral devices have operated according to various control codes.

Therefore, an object of the present invention is to provide an information processing system capable of transmitting a new control signal by using an existing control line and grasping various situations of peripheral devices.

Another object of the present invention is to provide an information processing system capable of confirming a new control signal when transmitting a new control signal to the control line.

[0010]

According to a first aspect of the present invention, there is provided a host device for transmitting data to a data line and receiving a control signal transmitted from a partner device via the control signal line. (B) Decoding means for receiving the data sent from the data transmission source through the data line and decoding the data, and a control signal to be sent to the control signal line when the decoding means decodes specific data. The information processing system is provided with a peripheral device having a control signal switching means for switching the type of the.

That is, according to the first aspect of the invention, when a peripheral device such as a print device has specific data, the type of the control signal to be sent to the control signal line is switched to be used for another purpose. A control line is used to send out a necessary control signal so that various conditions of the peripheral device can be notified to the host side.

According to the second aspect of the invention, (a) the data is sent to the data line and the control signal sent from the partner device via the control signal line is received, while the specific data is sent. A host device that confirms whether or not there is a change in the logic of the received control signal and fetches the control signal when the change is confirmed, and (b) data sent from this data transmission source via the data line. In the state where the type of the control signal is switched, the decoding means for receiving and decoding the control signal, the control signal switching means for switching the type of the control signal to be sent to the control signal line when the specific data is decoded An information processing system is provided with a peripheral device having a control signal logic changing means for changing the logic after a lapse of a predetermined time.

That is, according to the second aspect of the invention, when specific data is sent from the host to switch the control signal, the logic of the switched control signal is changed after a predetermined time, and the host device is changed. The peripheral side can confirm that the switching of the control signal is surely performed on the peripheral side. For example, when the signal state before the switching is at the H level and the signal state of the new control signal after the switching is at the H level, it cannot be confirmed that the switching has been performed. Since the logic is changed after the lapse of time, in this example, the H level is L
It will be changed to the level. Therefore, if such a change is made, it can be confirmed that the control signal has been normally switched. Control signal is H level,
Even when the L level is transmitted in three values instead of two values, the switching of the control signal can be confirmed by similarly confirming the change of the L level.

According to the third aspect of the invention, (a) the data is sent to the data line and the control signals sent from the partner device at the same time via the plurality of control signal lines are received, while the specific data is sent. A host device that determines the logics of these control signals that are received after being sent, and captures these control signals when it is confirmed that a predetermined logical relationship exists between these control signals; ) Decoding means for receiving the data sent from the data transmission source through the data line and decoding the data, and a control signal for sending to a plurality of control signal lines when the decoding means decodes specific data. Control signal switching means for switching types and logic conversion means for converting one type of control signal in a predetermined logical relationship while switching the types of control signals and allocating to the plurality of control signal lines. To and a e was peripherals to the information processing system.

That is, according to the third aspect of the invention, when specific data is sent from the host to switch the control signal, the control signal logic after switching is controlled by using a plurality of control signal lines. By changing between the signal lines, the host device side can confirm that the control signal is surely switched on the peripheral device side. That is, the logic of a predetermined plurality of control signal lines is checked, and if these have a predetermined logical relationship, it is considered that the control signals have been switched and the control signals are fetched.

[0016]

EXAMPLES The present invention will be described in detail below with reference to examples.

FIG. 2 shows each signal line in the cable in the information processing system in one embodiment of the present invention. The cable 13 connected between the personal computer 11 and the laser printer 12 has eight data lines 21, one strobe signal line 22, one acknowledge signal line 23, and one busy signal. Line 24,
One paper error signal line 25, one select signal line 26, one fault signal line 27, one prime signal line 28, one 5 volt power supply line 29,
A plurality of ground lines 30 are arranged. Here, the data line 21, the strobe signal line 22, and the prime signal line 28 are signal lines for sending data or control signals from the personal computer 11 to the laser printer 12, and the acknowledge signal line 23 and the busy signal line 24. , Paper error signal line 25, select signal line 26,
The fault signal line 27 and the prime signal line 28 are signal lines for sending a control signal from the laser printer 12 to the personal computer 11.

The paper error signal line 25 is a line for transmitting a paper error control signal for informing the personal computer 11 side that an error such as a paper jam has occurred in the laser printer 12, and the select signal line 26. H if online and not in error
It is a line for transmitting a level select control signal. The fault signal line 27 is a line for transmitting a fault control signal that becomes L level when the laser printer 12 has an error or a failure, and the prime signal line 28 resets the laser printer 12 from the personal computer 11. It is a line for transmitting a prime control signal for making a call.

FIG. 3 shows a schematic configuration of a laser printer used in this embodiment to help understanding of each signal. The laser printer has an engine section 31 as a main section. Engine part 31
In this method, a laser beam is irradiated onto the photosensitive drum to form an electrostatic latent image corresponding to image information, and the electrostatic latent image is developed by a developing device to form a toner image. This toner image is transferred onto a sheet by a transfer corotron, fixed, and then ejected outside the apparatus.

The engine control unit 32 is connected to a control panel 33 arranged on the upper portion of the main body of the apparatus to control input / output 3
4, the control of each unit of the engine unit 31 is performed. The engine unit 31 is controlled by a laser control 35 for modulating image information with respect to a semiconductor laser, a process control 36 for executing processes such as development and transfer using a photosensitive drum, and a paper feed tray. There is a paper feed control 37 and the like for controlling the conveyance of the paper to be fed. Engine control unit 3
2 controls the laser 35 using the image information developed by the image developing unit 39. This image development unit 39
The image information is transmitted to the computer via the data line 21 (FIG. 2) of the cable 13 connected to the host interface unit 41.

FIG. 1 shows a circuit configuration of a main part in such a laser printer. The laser printer includes a CPU (Central Processing Unit) 51, and is connected to each unit in the apparatus through a data bus 52. Of these, the ROM 53 is a read-only memory that stores programs for controlling the respective parts such as the panel control 34 and the laser control 35 described above. A program for switching the type of signal transmitted through the paper error signal line 25 is also stored here. The RAM 54 is a working memory that stores data temporarily required for these controls, and is composed of a random access memory. The I / O port 55 has a control panel 3
Various parts such as 3 (FIG. 3) are connected. As described with reference to FIG. 2, various signal lines such as the data line 21 and the paper error signal line 25 that form the cable 13 are connected to the host interface unit 41.

FIG. 4 shows a flow for switching control of the paper error signal line in the laser printer having the above-described structure. In addition, this switching control is
It is assumed that the newly required font is sent from the personal computer 11 (FIG. 2) to the laser printer 12 through the data line 21. That is, in this embodiment, the font is R of the laser printer 12.
The paper error signal line is used to confirm that the data is stored in the AM 54.

The CPU 51 shown in FIG.
The data sent by "ESC CR pH"
It is checked whether it is a command, an "ESC CR pL" command, or an "ESC CR pD" command (steps S101 to 103).
Here, "ESC" in these commands is an escape code, and after that, a character to be a normal print target is added to perform various mode settings required in this embodiment. In addition, "ESCCR p
The H command is "1B0D704" in hexadecimal notation.
8 "and the" ESC CR pL "command is" 1B "
0D704C ”. When the“ ESC CRpD ”command is written in hexadecimal, it becomes“ 1B0D7044 ”.

When any of these commands is applied, the laser printer 12 starts predetermined control different from the conventional laser printer. That is, "ESC C
When the RpH "command is decoded (step S10)
1; Y), the CPU 51 checks whether the font is stored in the RAM 54 from the personal computer 11 (step S104). When the storage is completed successfully (Y), the paper error signal line 25 is set to the H level to notify the personal computer 11 side that the storage is completed. When the font storage is not completed or there is some trouble, the CPU 51 sets the paper error signal line 25 to the L level (step S106). In this way, when the "ESC CR pH" command arrives, instead of sending the paper error control signal to the paper error signal line 25, the font setting control signal indicating whether or not the font setting is completed is sent. It will be.

On the personal computer 11 side, "ES
By monitoring the signal state of the paper error signal line 25 after sending the "C CR pH" command, it is possible to know whether the font has been set correctly in the laser printer 12.

However, there is one problem here. It is whether or not the laser printer 12 correctly decodes the "ESC CR pH" command and returns a signal according to the presence or absence of font setting. Even if the laser printer 12 is still sending out the paper error control signal without sending out such a font setting control signal, the personal computer 11 cannot identify this, resulting in an erroneous result. There is a risk of making a decision. In this embodiment, the "ESC CR pL" command is defined in order to solve such a problem.

That is, when the "ESC CR pL" command is decoded (step S102; Y), the CPU
Similarly, 51 checks the presence / absence of font setting (step S107), and if the font setting is completed successfully (Y), sets the paper error signal line 25 to the L level whose logic is the opposite of the previous one (step S106). ). In other cases, the H level is set (step S
105). That is, the personal computer 11 sends the "ESC CR pH" command to check the logic level of the paper error signal line 25, and then the "ESC CR pH" command.
If the CR pL "command is output, it is possible to confirm that the laser printer 12 side correctly interpreted these commands because the logic level of the paper error signal line 25 was inverted.

On the other hand, if the signal state of the paper error signal line 25 is not reversed even after the "ESC CR pL" command is sent, whether there is some trouble on the laser printer 12 side or these commands It can be judged that it was not sent correctly.

As described above, when the paper error signal line 25 is switched from the original paper error control signal transmission to the font setting control signal transmission, the laser printer 12
It is necessary to switch to the sending state of the paper error control signal again, except when all the operations of (3) are finished at this stage. The decoding of the "ESC CR pD" command (step S103) is performed for this purpose. That is, "ES" is sent from the personal computer 11 through the data line 21.
If a C CR pD ”command is sent (Y),
The CPU 51 causes the paper error signal line 25 to output the paper error control signal again (step S10).
8).

FIG. 5 shows an example of successful font setting.
Further, FIG. 6 shows examples of failures.
These drawings correspond to the conventional FIG. 9 except that the paper error control signal (PE signal) is added, and therefore the description thereof will be appropriately omitted.

In FIG. 5, when the "ESC CR pH" command is sent as data as shown in (a), the paper error control signal (e in the figure) becomes H level, and the font setting is successful. Is shown. When the "ESC CR pL" command is sent, the font setting control signal is changed to the L level. Then, when the "ESC CR pD" command is sent, the font setting control signal is switched to the original paper error control signal.

In the case of FIG. 6, since the font setting has failed, the paper error control signal (FIG. 5E) becomes L level when the "ESC CR pH" command is sent. When the "ESC CR pL" command is sent, the font setting control signal is changed to H level. Then, when the "ESC CR pD" command is sent, the font setting control signal is switched to the original paper error control signal.

Modification

In the embodiment described above, the personal computer 11 on the host device side sends the "ESC CR pL" command after the "ESC CR pH" command to invert the logic of the binary signal. The laser printer 12 on the device side may automatically reverse the logic.

FIG. 7 shows a flow for switching control of the paper error signal line in such a modification. This switching control is also performed by the personal computer 1
1 (FIG. 2), it is premised that a newly required font is sent to the laser printer 12 through the data line 21.

The CPU 51 shown in FIG.
The data sent by "ESC CR pH"
It is checked whether it is a command (step S
201). When the "ESC CR pH" command is decoded (Y), the CPU 51 determines that the personal computer 1
It is checked whether the font from 1 is stored in the RAM 54 (step S202). If the storage is completed successfully (Y), the paper error signal line 25 is set to the H level to notify the personal computer 11 side that the storage is completed (step S203).

After this, when a predetermined time t has elapsed (step S204; Y), the CPU 51 switches the paper error signal line 25 to the L level (step S20).
5). Then, when the time t further elapses (step S
206; Y), the CPU 51 causes the paper error signal line 25
To send a paper error control signal again (step S
207).

On the other hand, if the font setting has failed in step S202 (N), the CPU 51 sets the paper error signal line 25 to the L level (step S2).
08). Then, when the time t has elapsed (step S20
9; Y), the paper error signal line 25 is set to the H level this time (step S210). Then, when the time t further elapses (step S211; Y), the paper error control signal is again sent to the paper error signal line 25 to restore the original state (step S207).

In the above-mentioned embodiments and modified examples, one signal line called the paper error signal line 25 is used to send another control signal, but the logic is changed simultaneously to a plurality of control signal lines. The transmitted control signal can also be confirmed by transmitting the same control signal. That is, by comparing the logic levels of the signals appearing on the plurality of control signal lines at the same time, it is possible to confirm that the signals have been correctly switched when they have a predetermined logical relationship. At this time, the greater the number of control signal lines transmitting the same control signal, the less the occurrence of errors in confirmation.

Further, in the embodiments, the transmission of binary signals has been described, but it goes without saying that the present invention can be similarly applied to the transmission of multivalued signals such as ternary signals.

Regarding the three types of commands used in the embodiment, the result of any command can be generally confirmed, but a command for confirming only the result of a specific command should be set. May be. That is, instead of confirming the result of the command sent immediately before, a command for confirming the result of the most recent specific command or a command for confirming a certain state may be set. Examples of the latter command for confirming a certain state include a command for confirming whether or not the font symbol set (256 characters per byte) is of the type "Roman-8".

[0042]

As described above, claims 1 to 3 are as described above.
According to the described invention, since the control signal to be transmitted to the predetermined control signal line is switched by transmitting the specific data to the data line, a new control signal can be obtained without increasing the number of control signal lines. Of the information processing system, and can flexibly deal with changes and expansions of the information processing system.

According to the first aspect of the invention, the host device side such as a personal computer sends specific data to switch the control signal sent from the peripheral device side such as a laser printer or set the logical state. It can be performed. Therefore, with respect to the confirmation of the switching of the control signal, the confirmation work can be continued until the host device side has the initiative and can be confirmed any number of times, and high reliability can be ensured.

On the other hand, according to the second aspect of the present invention, once the host device side has sent the specific data, the peripheral device side switches the control signal, while the logic is changed after a lapse of a predetermined time to change the control signal. Since it is decided to send the control signal, it is possible to reduce the load on the host device side and perform the confirmation work of switching the control signal. Further, since the logic is changed and the control signal is transmitted after the elapse of a predetermined time, there is an advantage that the switching of the control signal can be confirmed by using one control signal line.

According to the third aspect of the invention, the control signal switching is confirmed by using a plurality of control signal lines in parallel, so that the confirmation work can be performed quickly. There is.

[Brief description of drawings]

FIG. 1 is a block diagram showing a main part of a circuit configuration of a laser printer that constitutes an information processing system according to an embodiment of the present invention.

FIG. 2 is a signal line connection diagram showing an arrangement of each signal line in the information processing system of the present embodiment.

FIG. 3 is a schematic configuration diagram showing a schematic configuration of a laser printer of this embodiment.

FIG. 4 is a flow chart showing a flow for control signal switching control of a paper error signal line of the present embodiment.

FIG. 5 is a timing chart showing changes in various signals when font setting is successful in this embodiment.

FIG. 6 is a timing chart showing changes in various signals when font setting fails in this embodiment.

FIG. 7 is a flowchart showing a flow for switching control of a paper error signal line in a modified example of the present invention.

FIG. 8 is a system configuration diagram showing an example of an information processing system.

9 is a timing chart showing the timing of transmission of data and control signals in the information processing system shown in FIG.

[Explanation of symbols]

11 ... Personal computer, 12 ... Laser printer, 13 ... Cable, 21 ... Data line, 25 ... Paper error signal line, 41 ... Host interface section, 51 ... C
PU, 53 ... ROM, 54 ... RAM

Claims (3)

[Claims] 1. A host device for sending data to a data line and receiving a control signal sent from a partner device via a control signal line, and a data sending source sending the data signal via the data line. The peripheral device comprises a decoding means for receiving data and decoding the data, and a control signal switching means for switching the type of control signal to be sent to the control signal line when the decoding means decodes specific data. An information processing system characterized by: 2. A method of changing the logic of a control signal received after transmitting specific data while transmitting data to a data line and receiving a control signal transmitted from a partner device via a control signal line. A host device that confirms the presence or absence and fetches the control signal in the state where the change is confirmed, and a decoding means that receives the data sent from this data transmission source via the data line and decodes it. Control signal switching means for switching the type of control signal to be sent to the control signal line when the decoding means decodes the specific data, and control for changing its logic after a lapse of a predetermined time while switching the type of control signal. An information processing system, comprising: a peripheral device having a signal logic changing unit. 3. A control signal that transmits data to a data line and receives control signals simultaneously transmitted from a partner device via a plurality of control signal lines, while receiving specific data and then receiving these control signals. And the host device that takes in these control signals when it is confirmed that a predetermined logical relationship exists between these control signals and the data transmission source from the host device via the data line. Decoding means for receiving the received data and decoding it, control signal switching means for switching the type of control signal to be sent to the plurality of control signal lines when the decoding means decodes the specific data, and control And a peripheral device having a logic conversion means for converting one type of control signal in the state of switching the signal type in accordance with the predetermined logical relationship and allocating to the plurality of control signal lines. The information processing system according to claim Rukoto.