JPH11167435A - Communication terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a communication terminal which can simultaneously reset all slave units and can reset all the units when any unit cannot output a signal without permitting the respective units to repeat resetting. SOLUTION: In the terminal, the plural slave units 2-1 and 2-2 are daisy chain connected to a master unit 1. Two signal lines (first signal line R-1 and second signal line R-2) connecting the respective slave units 2-1 and 2-2 in parallel to the master unit, MPU 20-1 outputting the signals from the slave units 2-1 and 2-2 to the first signal line R-1 and MPU 10 detecting signal input to the master unit 1 and outputting reset signals resetting the slave units 2-1 and 2-2 from the master uit1 to the second signal line R-2 are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication terminal device having, for example, a G3 facsimile machine as a main device (master unit), and in particular, a plurality of subordinate devices (slave units) such as, for example, a G4 option board and a printer board. The present invention relates to a chain-connected communication terminal device.

[0002]

2. Description of the Related Art Conventionally, for example, a G3 facsimile
In some cases, various option boards such as a facsimile function option board and a printer option board are connected in a daisy chain to extend the function. In this case, the main body of the G3 facsimile apparatus is a master unit, and the other option boards function as slave units. Also, a personal computer is further daisy-chain connected to such a communication terminal device,
A configuration is also conceivable in which bitmap image data created by a personal computer is temporarily transferred to the main body of the facsimile apparatus and printed out using an option board of the printer, or directly transmitted by facsimile.

FIG. 3 is a block diagram showing a configuration example of a conventional communication terminal device in which a plurality of slave units are connected to such a master unit. In FIG. 3, reference numeral 1 denotes a master unit, and a plurality of units (two in this example)
Slave units 2-1 and 2-2 are daisy-chain connected in this order. Note that slave units 2-1 and 2-
2 can take various forms, such as an option board that can be attached to and detached from the master unit 1 or an integrated circuit that is fixed on the board of the master unit 1. On the other hand, they are connected in a daisy chain.

In the master unit 1, at least an MPU
10 and a memory (RAM) 50 are provided. In addition, each slave unit 2-1 and 2-2 also has at least MPU 20
-1, 20-2 and DPRAM (dual port RAM) 21-1, 21-2
Is provided. The master unit 1 and each of the slave units 2-1 and 2-2 have their own RAM 50 and DPRAM 21-.
Data transfer is performed asynchronously via 1, 21-2.

Data transfer between the RAM 50 and the DPRAM 21-1 is performed as follows.
Master unit 1, slave unit 2-1 and DPRAM 21-1
The bus line B-0 connects the MPU 10 and the RAM 50 in the master unit 1. Data transfer between the DPRAMs 21-1 and 21-2 is performed via a bus line B-1 connecting the slave unit 2-1 and the DPRAM 21-2 of the slave unit 2-2. The line B-1 connects the MPU 20-1 and the DPRAM 21-1 in the slave unit 2-1. In addition, DPRAM 21-1 and other slave units
Data transfer between DPRAMs is performed via a bus line B-2 connecting the slave unit 2-2 to another slave unit. The bus line B-2 is connected to the MPU 20 in the slave unit 2-2. -2 and DPRAM 21-2.

In such a conventional communication terminal device in which a plurality of slave units 2-1 and 2-2 are daisy-chain connected to such a master unit 1, any one of the master unit 1, the slave units 2-1 and 2-2 is used. If an error is detected in the, it is necessary to reset all daisy-chained units in order to return the hardware settings such as the association with the connected units to the initial state.

For this reason, for example, a configuration in which a reset signal line is provided between each unit is considered. In this configuration,
For example, when an abnormality is detected in the slave unit 2-1, the MPU 20-1 resets itself and transfers a reset signal to the master unit 1 and the slave unit 2-2.

[0008] The MPU 10 of the master unit 1 and the MPU 20-2 of the slave unit 2-2 to which the reset signal has been applied reset themselves, and the slave unit 2-2.
MPU 20-2 transfers the reset signal to the next slave unit connected via the bus line B-2. further,
When other slave units are daisy-chain connected, the transfer of the reset signal is repeated according to the above procedure.

[0009]

However, in order for each unit to send a reset signal to another adjacent unit, each unit takes measures such as invalidating a reset signal given after each unit resets itself. Unless there is a problem, there is a problem that an adjacent unit sends a reset signal to a unit that has already completed resetting and repeats resetting.

In addition, when this unit is in a state where it cannot output a signal, such as when the power supply of any unit is OFF, and when an abnormality is detected in another unit, the reset signal is output to all the units. The problem of not being transferred to the unit arises.

The present invention has been made in view of such circumstances, and two signal lines branched from a master unit and connected in parallel to each slave unit are provided. By giving a signal from the slave unit to the master unit via the signal line, the master unit resets itself in response to this signal, and by giving a reset signal from the master unit to all slave units via the other signal line. ,
A facsimile machine that can reset all slave units at once, without resetting each unit, and resetting all units even when any unit cannot output a signal. It is an object to provide such a communication terminal device.

[0012]

According to a first aspect of the present invention, there is provided a communication terminal device wherein a plurality of subordinate devices are daisy-chain-connected to a main device. A signal line, means for outputting a signal from the slave device to one signal line, means for detecting a signal input to the main device, and a reset signal for resetting the slave device from the main device to the other signal line in response to the detection Output means.

The communication terminal device according to a second aspect of the present invention is the communication terminal device according to the first aspect, wherein the means for outputting the reset signal outputs a reset signal to all the slave devices simultaneously, and the one signal line Means for outputting a signal to the slave device after the reset signal is supplied to the slave device.

A communication terminal according to a third aspect of the present invention is the communication terminal according to the first or second aspect, wherein the one signal line prevents signal interference from a slave device to another slave device. A buffer and a write port for generating the reset signal to the main device are interposed, and the other signal line is provided with a write port for generating the reset signal from the main device. .

According to the communication terminal device according to the first and third aspects of the present invention, in a device in which a plurality of slave units as slave devices are daisy-chain connected to a master unit as a main device, the slave unit is connected to the master unit. Two signal lines connected in parallel (for example, each signal line is a first signal line and a second signal line) are provided, a signal is output from the slave unit to the first signal line, and the signal is output to the master unit. Has a configuration in which a reset signal is output to the second signal line in response to the above, so that each unit does not repeat resetting, and a signal line is provided as a bypass that does not pass through a daisy chain bus line. Each unit can be reset even when any of the slave units cannot output a signal.

According to the communication terminal device of the second invention, since the reset signal is outputted from the master unit to all the slave units, all the slave units can be reset at the same time. Since the means for outputting a signal to the one signal line (first signal line) is configured to prohibit outputting the signal after the reset signal is given, the slave unit may repeatedly reset the master unit. Absent.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings showing the embodiments. FIG. 1 is a block diagram showing one configuration example of a communication terminal device (hereinafter, referred to as the present device) according to the present invention.

In FIG. 1, reference numeral 1 denotes a master unit (main device) configured as a G3 standard facsimile apparatus main body, which includes at least an MPU 10 and a memory (RAM) 50. An encoding / decoding circuit (CODEC), a network control circuit (NCU) and the like are also provided, but are omitted here.

A plurality of (two in the example shown in FIG. 1) slave units (subordinate devices) 2-1 and 2-2 are daisy-chain connected to the master unit 1, which is the main body of the facsimile apparatus. However, in this example, the slave unit 2-1 configured as a G4 board includes at least the MPU 20-1 and the DPRAM 21-1.
For example, a codec required for the board is also provided, but is omitted here. In addition, the slave unit 2-2 configured as a printer board is provided with at least the MPU 20-2 and the DPRAM 21-2, and is further provided with a printer interface required as a printer board, for example. It is omitted here. The slave units 2-1 and 2-2 also store software programs necessary to realize their functions.
Although a ROM is provided, it is omitted in FIG.

Master unit 1 and slave unit 2-1
Are connected by a bus line B-0. Specifically, the RAM 50 and MPU 10 in the master unit 1 and the DPRAM 21-1 in the slave unit 2-1 are connected by a bus line B-0. The slave unit 2-1 and the slave unit 2-2 are connected by a bus line B-1. Specifically, DPRAM 21-1 and MPU in slave unit 2-1
20-1 and DPRAM 21-2 in the slave unit 2-2 are connected by a bus line B-1. Further, the DPRAM 21-2 and the MPU 20-2 in the slave unit 2-2 are connected to a bus line B-2, and another slave unit is connected to the bus line B-2.

The data input to the bus line B-2 is temporarily written to the DPRAM 21-2 of the second-stage slave unit 2-2. Next, the DPRAM of this slave unit 2-2
Data is read out from 21-2 and is temporarily written to DPRAM 21-1 of the first-stage slave unit 2-1. Finally, data is read from the DPRAM 21-1 of the slave unit 2-1 and written to the RAM 50 of the master unit 1.

The output terminal of the reset signal provided in the MPU 10 in the master unit 1 is connected to a second signal line R-2. Write port that generates a reset signal output from
30 are interposed. The second signal line R-2 on the output terminal side of the buffer 40 is divided into the number of slave units 2-1 and 2-2, and each divided end is connected to each of the slave units 2-1 and 2-2.
It is connected to MPU 20-1 and 20-2 in 2-2.

On the contrary, each slave unit 2-1,
The output terminals of the MPUs 20-1 and 20-2 in 2-2 are respectively connected to a plurality of divided first signal lines R-1. 1st signal line R-
The write ports 30-1 and 30-2 for generating the reset signal and the slave units 2-1
Buffers 40-1 and 40- that prevent signal interference between
And 2 are interposed in series. Each buffer 40-1, 40-2
The first signal line R-1 on the output terminal side is converged to one signal line and connected to the input terminal of the master unit 1.

The MPU 20 in each of the slave units 2-1 and 2-2
-1, 20-2 are the own and other slave units 2-1 and 2-2
Outputs a signal to the first signal line R-1 when any abnormality is detected. On the other hand, MPU 10 in master unit 1
Resets itself and sets the first signal line R-1
A reset signal is simultaneously output to the MPUs 20-1 and 20-2 of all the slave units 2-1 and 2-2 in response to a signal given through the CPU.

When an abnormality is detected in the master unit 1, the master unit 1 is first reset itself, and all the slave units 2--1 are reset according to the signal supplied through the first signal line R-1. 1, 2-2
A reset signal is simultaneously output to the MPUs 20-1 and 20-2.

The MPUs 20-1 and 20-2 of the slave units 2-1 and 2-2 to which the reset signal has been applied reset themselves. At this time, each slave unit 2-1 and 2-2
Is the master unit 1 or another slave unit 2-1,
No reset signal is output for 2-2.

FIG. 2 is a flowchart showing a procedure in which the MPU 10 of the master unit 1 outputs a reset signal when an abnormality is detected in any of the units of the present invention shown in FIG. This is described below with reference to FIG.

The MPU 10 is in a signal waiting state (step 1), and repeats step 1 at a predetermined time period until a signal is detected at its input terminal. Then, as the signal is detected, first, the master unit 1 itself is reset (step 2), and a reset signal is sent from the output terminal of the MPU 10 to all the slave units 2-1 and 2-2. Output (Step 3).

[0029]

As described in detail above, according to the communication terminal device of the present invention, in a device in which a plurality of slave units as slave devices are daisy-chain-connected to a master unit as a main device, Two signal lines for connecting slave units in parallel (for example,
Each signal line is provided as a first signal line and a second signal line), and a signal is output from the slave unit to the first signal line.
In response to this signal, the master unit outputs a reset signal to the second signal line so that each unit does not repeat resetting, and a signal line is provided as a bypass that does not pass through a daisy chain bus line. Therefore, each unit can be reset even when any of the slave units cannot output a signal.

By outputting a reset signal from the master unit to all the slave units, all the slave units can be reset at the same time, and a signal is sent to the one signal line (first signal line). The present invention has an excellent effect such that the slave unit does not repeatedly reset the master unit by prohibiting the output of the signal after the reset signal is supplied, thereby preventing the slave unit from resetting the master unit.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration example of a communication terminal device according to the present invention.

FIG. 2 is a flowchart illustrating a procedure in which an MPU of a master unit outputs a reset signal when an abnormality is detected in any of the units.

FIG. 3 is a block diagram showing a configuration example of a conventional communication terminal device in which a plurality of slave units are connected to a master unit.

[Explanation of symbols]

 1. Master unit (fax machine) 2-1 Slave unit (G4 board) 2-2 Slave unit (modem board) 10, 20-1, 20-2 MPU 30, 30-1, 30-2 Write port 40-1 , 40-2 Buffer 50 Memory (RAM) R-1 First signal line R-2 Second signal line

Claims (3)

[Claims] 1. A device in which a plurality of slave devices are daisy-chain-connected to a main device, two signal lines for connecting each slave device to the main device in parallel, and a signal from the slave device to one signal line. A communication terminal comprising: a unit for outputting a signal; a unit for detecting a signal input to the main device; and a unit for outputting a reset signal for resetting a slave device from the main device to the other signal line in response to the detection. apparatus. 2. The means for outputting a reset signal outputs a reset signal to all slave devices at the same time, and the means for outputting a signal to the one signal line includes a signal after the reset signal is given. 2. The apparatus according to claim 1, wherein output of the signal from a slave device is prohibited.
The communication terminal device according to claim 1. 3. The one signal line includes a buffer that prevents signal interference from a slave device to another slave device, and a write port that generates the reset signal to a main device. The communication terminal device according to claim 1, wherein a write port for generating the reset signal from a main device is interposed in the other signal line.