JPH04196742A - data transmission equipment - Google Patents

Abstract

PURPOSE:To allow the operator to immediately recognize mis-connection and to protect the circuit and the station installation by raising an alarm of mis- connection when data transmission is started and a voltage is impressed externally to a telephone terminal. CONSTITUTION:In the case of starting data transmission, whether or not a voltage is impressed externally to a telephone terminal 2 is detected by a loop current detection section 3, and while usual data transmission and impression of a voltage to the telephone terminal 2 are started when no voltage is impressed thereto, when a voltage is impressed to the telephone terminal 2, an alarm representing mis-connection is raised. Thus, the operator immediately recognizes mis-connection to prevent damage to the device or installation and prescribed communication is always implemented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a data transmission device that performs communication by connecting a telephone line and a telephone set.

[Prior Art] A facsimile machine used on a telephone line is usually provided with a line terminal for connecting the telephone line and a telephone terminal for connecting a telephone for making calls.

These terminals often have the same shape, such as modular jacks.

For this reason, when installing a facsimile machine, you may accidentally
There were cases where the telephone line was connected to the telephone terminal side and the telephone set was connected to the line terminal side.

If this connection is made incorrectly, the facsimile machine will not operate when a call arrives or when the operator activates facsimile communication.

On the other hand, when a facsimile machine is not operating,
The line terminal and telephone terminal are connected inside the device. As a result, even if a connection is made incorrectly, calls can be made without any problem. Therefore, the operator did not easily notice the incorrect connection.

Furthermore, some facsimile machines apply a constant voltage to a connected telephone to detect its hooked state. If such a facsimile device is incorrectly connected, the line voltage of the telephone line will be applied to the circuit that generates the constant voltage. In this case, there was a risk of damage to the circuit or equipment at the telephone office.

[Problem to be solved by the invention] As described above, in the past, if a telephone set or telephone line was incorrectly connected, the operator could not easily notice it, and there was a risk of damage to equipment and station equipment. In addition, there was a problem that facsimile communication was not possible.

Note that this kind of problem is not limited to facsimile machines.
The same applies to various data transmission devices that use modems to transmit data over telephone lines.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and provide a data transmission device that allows an operator to immediately know about erroneous connections and prevent damage to devices and equipment, while also allowing predetermined communications to be performed at all times.

[Means for Solving the Problems] To this end, the first invention of the present application detects whether or not voltage is being applied from the outside to the telephone terminal when starting data transmission, and detects whether or not voltage is being applied to the telephone terminal. If no voltage is applied to the telephone terminal, data transmission and voltage application to the telephone terminal will start as usual, but if voltage is applied to the telephone terminal, an alarm will be output indicating that there is an incorrect connection. There is.

Further, in the second invention, when a voltage is applied to the telephone terminal, data is transmitted by transmitting and receiving signals to the telephone terminal side.

[Operation] If the telephone line and telephone are incorrectly connected, the line voltage of the telephone line will be applied to the telephone terminal.

In this case, in the first invention, since a warning is output, the operator can immediately notice the incorrect connection, and
In that case, since no voltage is applied to the telephone terminal, circuits and station equipment can be protected.

Furthermore, in the second aspect of the invention, if there is an incorrect connection, data signals are transmitted and received on the telephone terminal side to which the telephone line is connected, so that predetermined communications can always be performed.

[Embodiments] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows a block diagram of a facsimile machine according to a first embodiment of the present invention.

In the figure, line terminal 1 is for connecting a telephone line, and its two lines are connected to contact point al of switch circuit S1.
ral respectively. The telephone terminal 2 is used to connect a telephone, and one line thereof is connected to the contact C3 of the switch circuit S2 via the contact b1 of the switch circuit S1 and the loop current detection section 3. The other line is connected to the contact point C4 of the switch circuit S1 and the common contact point C4 of the switch circuit S2.

The common terminal c1 of the switch circuit S1 is connected to the ringing detection section 4, the contact a of the switch circuit S2, and one end of one winding of the transformer 5.

Further, the common terminal C1 of the switch circuit $1 is connected to the ringing detection section 4 and the contact a of the switch circuit S2 via the polarity reversal detection section 6, and the line is further connected via the switch circuit S3. It is connected to the other end of the winding.

Both ends of the other winding of the transformer 5 are connected to a facsimile image processing section 7. Contact point of switch circuit S2,
, b, are connected to the line voltage generator 8.

The control section 9 monitors and controls each of the above sections, and includes the loop current detection section 3. Detection signals are input from the ringing detection section 4 and polarity reversal detection section 6, respectively, and operation information is input from the operation display section 10, while switch circuits 81 to S3. Control signals are output to the facsimile image processing section 7 and the operation display section 10, respectively.

When using the facsimile apparatus of this embodiment with the above configuration, a telephone line is connected to the line terminal 1, and a telephone (not shown) is connected to the telephone terminal 2.

FIG. 2 shows the communication operation of this facsimile machine. That is, when the facsimile machine is turned on, the switch circuits Sl and S2 are connected to contacts a.
side and open the switch circuit S3 (process 101).
, waits (N loop of processing IO2).

At this time, the telephone sets switch circuit S2. Loop current detection section 3. It is connected to a telephone line via the polarity reversal detection section 6 and switch circuit S1. This allows the operator to freely use the telephone for making calls.

On the other hand, when a call arrives on the telephone line in the standby state, the ringing detection section 4 detects an ear-high signal from the line. Further, when performing facsimile communication, the operator performs a predetermined activation operation on the operation display section 10.

When the facsimile machine receives a call or performs a startup operation (Y in process 102), it switches the switch circuit S1 to the contact side and closes the switch circuit S3 (process l○3). Then, the loop current detection unit 3 detects whether a loop current flows in the line of the telephone terminal 2 (
Process 104).

If the telephone is correctly connected to telephone terminal 2,
The above loop current does not flow. In this case (N of process 104
), the switch circuit S2 is switched to the contact side, and the switch circuit S1 is switched to the contact a side (processing 1o5). As a result, the telephone line is connected to the polarity reversal detection section 6 and the switch circuit S.
3 to the winding of the transformer 5. The facsimile image processing unit 7 transmits and receives facsimile signals to and from the telephone line to execute predetermined facsimile communication.

Further, a constant voltage is applied to the telephone terminal 2 from the line voltage generator 8 . Thereby, when the telephone is off-hook, the current flowing through the line of the telephone terminal 2 causes the one-hull current detection section 3 to detect the off-hook.

If the operator takes the phone off-hook during a call,
After transmitting the image information, the facsimile machine performs a known conversation procedure to enable the operator to speak.

Note that the polarity reversal detection unit 6 detects a response from the other party when a call is made or a disconnection of the other party's line during communication by determining the polarity of the line voltage. As a result, the communication procedure being executed is stopped as necessary (process 106).

By the way, I accidentally connected a phone to line terminal 1,
Assume that a telephone line is connected to telephone terminal 2.

In case 2, since a line voltage of 48 V DC is applied to the telephone terminal 2, a loop current is detected in the above process 104. In this case (Y in process 104),
As an alarm display, for example, a message such as "The line connection is incorrect" is displayed on the display of the operation display unit 10, and an alarm sound is outputted with a buzzer or the like (process 107). Then, it returns to the standby state without operating (proceed to process 101).

As described above, in this embodiment, when starting a communication operation, it is detected whether or not voltage is applied from the outside to the telephone terminal 2, and if voltage is applied, an alarm is displayed. That's what I do. This allows the operator to immediately notice if there is an incorrect connection.

In addition, in the case of incorrect connection, since no voltage is applied from the line voltage generator 8 to the telephone terminal 2, the line voltage may be applied to the line voltage generator 8 and the circuit may be damaged, or the generated voltage of the circuit may This eliminates the risk of damage to telephone office equipment.

Next, a second embodiment of the present invention will be described.

In this embodiment, in addition to the facsimile machine shown in FIG. 1, another switch circuit S4 is added as shown in FIG.
has been set up.

That is, the two lines of the telephone terminal 2 are connected to contacts S, , B of the switch circuit S1 and contacts S, , S of the switch circuit S4, respectively.

In addition, the two lines of line terminal l are connected to switch circuit $1.
Contacts a, , a, and contacts of switch circuit S4, , b
. are connected to each. And switch circuit $
4 is connected to the contact c4 of the switch circuit S2, and the contact C1 of the switch circuit S4 is connected to the loop current detection section 3.
The contact c3 of the switch circuit S2 is connected to the contact c3 of the switch circuit S2.

In this case, the facsimile machine, as shown in FIG.
Switch circuits Sl, S3. S4 is connected to the a side, the switch circuit S2 is opened (process 201), and the process waits (N loop of process 202).

Then, when there is an incoming call or a start-up operation (Y in process 202), the switch circuit S1 is switched to the b side and the switch circuit S2 is closed (process 203), as in the previous embodiment.
Check the loop current (process 204).

If the connection is correct and there is no loop current (N in process 204), switch the switch circuit S2 to the b side and return the switch circuit S1 to the a side (process 205).
A predetermined facsimile communication is executed (process 206).

On the other hand, if the connection is incorrect and there is a loop current (Y in process 204), switch circuit S4 is switched to the b side, and then switch circuit S2 is switched to the b side (process 2
07).

As a result, the telephone line is connected to the transformer 5 to enable facsimile communication, and a predetermined voltage is applied to the telephone from the line voltage generator 8, so that the hook state can be detected. become.

In this state, predetermined facsimile communication is executed (processing 2
to 06).

As described above, in this embodiment, when a connection is made incorrectly, facsimile signals are sent and received to the telephone terminal 2 side, and the voltage of the line voltage generator 8 is applied to the line terminal l side.
The hook state is detected.

As a result, even in an incorrectly connected state, predetermined communications can be performed in exactly the same way as in a correctly connected state.

In addition, in each of the above embodiments, when determining whether or not a telephone line is connected to the telephone terminal 2 side, the loop current detection section 3 that detects the hook state of the telephone is used. Although this detection circuit is no longer necessary, it is of course possible to provide an independent circuit for detecting the voltage applied to the telephone terminal 2.

Further, although the explanation has been given using a facsimile machine as an example, it goes without saying that the present invention is similarly applicable to not only facsimile machines but also various data transmission devices that transmit data over a telephone line using a modem.

[Effects of the Invention] As described above, according to the first invention of the present application, when voltage is applied from the outside to the telephone terminal when data transmission is started, a warning is issued to the effect of incorrect connection. I did it like this,
The operator can immediately notice the incorrect connection, and in that case, no voltage is applied to the telephone terminal, so the circuit and station equipment can be protected. , ii Since data signals are sent and received to and from the talk terminal side, predetermined communication can always be performed.

[Brief explanation of the drawing]

FIG. 1 is a circuit configuration diagram of a facsimile machine according to a first embodiment of the present invention, FIG. 2 is a flowchart of communication operation in that embodiment, and FIG. 3 is added to FIG. 1 in a second embodiment. FIG. 4, which is a circuit diagram of the peripheral portion of the switch circuit, is a flowchart of the communication operation in this embodiment. 1... Line terminal, 2... Telephone terminal, 3... Loop current detection section, 4... Linking detection section, 5. Transformer, 6... Polarity reversal detection section, 7... Fadasimile image Processing unit, 8, line voltage generation unit, 9...control unit, 10
...Operation display section, St-S4...Switch circuit.

Claims (2)

[Claims] (1) A line terminal for connecting a telephone line, a telephone terminal for connecting a telephone, a voltage applying means for applying a constant voltage to the telephone terminal during communication operation, and a telephone depending on the presence or absence of current flowing from the voltage applying means. In the data transmission device, the data transmission device is provided with a hook state determination means for determining the hook state of the telephone terminal, and transmits data via the connected telephone line, in which a voltage is externally applied to the telephone terminal when data transmission is started. detection means for detecting whether or not a voltage is applied to the telephone terminal; operation starting means for starting data transmission and application of voltage to the telephone terminal by the voltage application means when no voltage is applied to the telephone terminal; 1. A data transmission device comprising: an alarm means for outputting an alarm to the effect that there is an erroneous connection when the voltage is applied. (2) In a data transmission device that is equipped with a line terminal for connecting a telephone line and a telephone terminal for connecting a telephone, and transmits data via the telephone line to be connected, when starting data transmission, the telephone terminal a detection means for detecting whether or not voltage is applied from the outside to the telephone terminal; and normal communication means for transmitting and receiving signals to and from the line terminal to perform data transmission when no voltage is applied to the telephone terminal; A data transmission device comprising: an erroneous connection communication means for transmitting and receiving signals to and from the telephone terminal to perform data transmission when a voltage is applied to the telephone terminal.