JPH0426263B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an interface used to interface a central control unit (CPU) and a network control unit (NCU) connected to a public network. The present invention relates to a conversion device, and particularly relates to an interface conversion device used when transmitting 200 series signal information of Recommendation V.24 of the Consultative Committee for International Telegraph and Telephone (CCITT) using the public network.

[Conventional technology]

When performing data communication between the CPU and terminal equipment (DTE), if a public network can be used, the CPU, DTE
In areas where public networks are well-developed, the use of public networks provides an invaluable advantage to data communication systems, since individual connections with cables or the like are no longer necessary, and the public networks do it for them.

When using a public network for data communication between the CPU and DTE, normally the CPU1
1 and public network 12 and between public network 12 and DTE 1
3, respectively, network control unit (NCU) 1
4 and 15 are required. In addition, 16 and 17 are
Transmission lines 18 and 19 are transmission lines for CCITT recommended 100 series signals (serial signals), 21 and 22 are modem modulators (MODEM), respectively.

Here, CPU 11, NCU 14 and public network 12
When considering the investment effect in the case where the distance between That is, the fourth
In the figure, MODEM 21 is located at substantially the same position as NCU 14.

[Problem that the invention seeks to solve]

In a system in which the distance L between the CPU 11, NCU 21, and public network 12 is long as shown in FIG. It is possible. However, the signals specified in the 200 series of V.24 are parallel signals, so
As the distance L increases, the data characteristics deteriorate,
Moreover, there is a limit to the distance that parallel lines can be drawn. There are no known devices that effectively transmit V.24 200 series signals.

The purpose of the present invention is to solve the problem of V.24 200 when there is a large distance between the above CPU, NCU and public network.
The object of the present invention is to provide a device that can effectively transmit a series of parallel signal information.

[Means for solving problems]

The present invention supports 200 series parallel signals of V.24.
Convert to V.24 100 series serial signal, and
This is an interface conversion device that converts V.24 100 series serial signals to V.24 200 series parallel signals.

That is, according to the present invention, a first interface circuit having a first input terminal for receiving a first parallel signal and a first output terminal for outputting a second parallel signal; a second interface circuit having a second input for receiving a signal and a second output for outputting a second serial signal;
an encoding circuit that receives a third parallel signal obtained by converting the level of the first parallel signal at the input terminal of the input terminal by the first interface circuit, encodes it into a corresponding serial signal, and outputs the encoded signal; said first at the end
a decoding circuit that receives a third serial signal whose level has been converted by the second interface circuit, decodes it into a corresponding parallel signal, and outputs the same, the second interface circuit: The output signal of the encoding circuit is level-converted and outputted as the second serial signal to the second output terminal, and the first interface circuit is configured to level-convert the output signal of the decoding circuit and output it to the second output terminal as the second serial signal. There is obtained an interface conversion device characterized in that the second parallel signal is output to the first output terminal.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

Referring to FIG. 1, an interface conversion device 20 according to an embodiment of the present invention has a first input terminal IN1 receiving a first parallel signal 21 which is a V.24 200 series signal, and a V.24 a first interface circuit (V.24 200 series interface circuit) having a first output terminal OUT1 for outputting a second parallel signal 22 which is a 200 series signal of V.24;
31, and a second input terminal IN2 receiving a first series signal 41 which is a V.24 100 series signal;
A second interface circuit (V.24 100 series interface circuit) 52 having a second output terminal OUT2 for outputting a second serial signal 42 which is a V.24 100 series signal; have.

The V.24 200 series parallel signal 21 output from the CPU etc. is input to the V.24 200 series interface circuit 31, and the next encoding circuit 61 is a signal such as TTL level that is easy to logically process. (3rd
parallel signals) 63 and sent to the encoding circuit 61. This encoding circuit 61 analyzes the 200 series parallel signal information 63 sent from the interface circuit 31, and converts it into V.24 100 series transmission data according to predetermined encoding rules. It is encoded into a serial signal that can be interfaced and sent to the V.24 100 series interface circuit 52. The V.24/100 series interface circuit 52 converts the level of the output signal of the encoding circuit 61 and outputs it as a second serial signal 42 to the second output terminal OUT2.

Conversely, the serial V.24 100 series signal information 41 input to the V.24 100 series interface circuit 52 is a signal (third serial signal) 83 at a level that can be processed by the next decoding circuit 81. converted to
It is sent to the decoding circuit 81. The decoding circuit 81 analyzes this serial signal 83 and decodes the original V.24 200
It is decoded into series parallel signals and sent to the V.24 200 series interface circuit 31. V.24・
In the 200 series interface circuit 31, this
Level conversion is performed on the 200 series information so that it can be interfaced with the CPU, etc., and then sent as a second parallel signal 22 from the first output terminal OUT1 to the CPU, etc.

FIG. 2 shows an interface conversion device 20 of the present invention.
A system configuration diagram using . In FIG. 2, 23 represents a set of signal lines for transmitting the signals 21 and 22 of FIG. 1, and 43 represents a set of signal lines for transmitting the signals 41 and 42 of FIG. .

The CPU controls the NCU 14 and performs data communication with a terminal device (not shown) via the public network 12.
11 sends a V.24 200 series parallel signal to the interface converter 20 according to the present invention.
As described above, this interface conversion device 20 analyzes and encodes the transmitted V.24 200 series signal, and outputs it as a transmission data signal of the V.24 100 series signal. V.24
The signal encoded in the 100 series can be transmitted by using modulation/demodulation devices (MODEM) 91 and 92, etc., and is transmitted to the interface conversion device 20 according to the present invention. In addition, MODEM
91 and 92 are connected by a wired line. In this interface conversion device 20, the transmitted
The information of the V.24 200 series signal encoded in the transmission data of the V.24 100 series signal is decoded and output to the NCU 14 as the V.24 200 series signal.

Conversely, the V.24 200 series signal output from the NCU 14 and transmitted to the interface converter 20 is also converted into a V.24 100 series signal within this interface converter 20 by the same means.
The signal is transmitted to the interface converter 20 through the modulation/demodulators 92 and 91, converted again to the original V.24 200 series signal within the interface converter 20, and transmitted to the CPU 11.

It can be seen that the above operation enables data communication even in the system configuration shown in FIG. 4.

〔Effect of the invention〕

As explained above, according to the present invention, the CPU and
This provides an interface conversion device that can effectively transmit V.24 200 series parallel signal information when there is a large distance between the NCU and the public network.

Furthermore, the interface conversion device according to the present invention
By introducing between CPU and NCU, CPU
This eliminates the inconvenience caused by the distance between the network and the NCU, and has the effect of reducing the cost invested in the public network.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an interface conversion device according to an embodiment of the present invention, and FIG. 2 is a block diagram showing an interface conversion device according to an embodiment of the present invention.
Figure 3 is a block diagram showing a system that uses a public network when the distance between the CPU and NCU is long. FIG. 4 is a block diagram showing a conventional system when the distance between the CPU and the NCU is long. In FIG. 3, 20...interface conversion device, 31...200 series interface circuit of V.24, 52...100 series interface circuit of V.24, 61...encoding circuit, 81...decoding circuit.

Claims (1)

[Claims] 1. A first interface circuit having a first input terminal for receiving a first parallel signal and a first output terminal for outputting a second parallel signal; and a first serial signal. a second interface circuit having a second input for receiving the first parallel signal and a second output for outputting a second serial signal; an encoding circuit that receives a third parallel signal level-converted by the interface circuit, encodes it into a corresponding serial signal, and outputs it;
The third level is converted by the interface circuit of
a decoding circuit that receives a serial signal, decodes it into a corresponding parallel signal, and outputs it, and the second interface circuit converts the level of the output signal of the encoding circuit and outputs the parallel signal. Said second as a signal
, and the first interface circuit converts the level of the output signal of the decoding circuit and outputs it as the second parallel signal to the first output terminal. Ace conversion device. 2 The first and second parallel signals are CCITT Recommendation V.24
The interface converter according to claim 1, wherein the first and second serial signals are 100 series signals of CCITT Recommendation V.24.