JPH05211575A - Ncu modem controller - Google Patents

Abstract

PURPOSE:To widen the utilization environment of communication software for a special leased line by obtaining a network control command from a network control command/response communication interface circuit and controlling an input/output circuit for special signal line control. CONSTITUTION:An internal connection line 4 for data communication is connected to a terminal 7 through a cable 6. When the terminal 7 makes a call, a call command is sent to the NCU model controller 1 through a cable 8. The controller 1 outputs a signal that an NCU model 2 can recognize to the modem 2 through a cable 3. The model 2 automatically dials a predetermined telephone number and informs the controller 1 of the establishment of a data communication link once the link is established. The controller informs the terminal 7 of the correct origination through the cable 8. The terminal actuates the communication software for the specific leased line.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an NCU modem controller,
In particular, using a public telephone line modem for the public telephone line network,
NC when using communication software for specific leased line
U-modem controller

[0002]

2. Description of the Related Art Conventionally, when performing this type of communication, CCI
V. defined by TT. RS232C (V.25) for communication is used by using a modem having a network control command standard such as 25 bis.
24) A method of performing network control and data communication by one channel via a channel, and a modem having only the data communication function without the network control function and an NCU for performing the network control are individually prepared, and the NCU and the terminal are provided. There is a method in which network control is performed in a specific procedure and data communication is performed in another channel.

[0003]

In the above-mentioned first conventional method, the communication software is V. Although it is necessary to support the 25bis command standard, communication software for a specific leased line cannot be used because it does not need to perform network control and does not support this.

In the second method, the interface for controlling the NCU from the terminal is not a general standard,
Difficult to use.

[0005]

The NCU modem control unit of the present invention can perform network control such as automatic call origination, incoming call detection, carrier signal detection, etc. by specific signal line control of RS232C (V.24) standard. It is located between the NCU modem for public telephone line and the terminal, and has a channel for transmitting and receiving public line automatic call control commands in addition to the data communication channel. From the network control command / response communication interface circuit It is characterized in that a network control command is obtained and the input / output circuit for controlling the specific signal line is controlled.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention.

The NCU modem control device 1 and the NCU modem 2 are connected by an NCU modem connection cable 3 of RS232C (V.24) standard.

In the NCU modem control unit 1, the NCU modem connection cable 3 does not connect only the ER and CI signal lines in the NCU modem connection cable 3 to the data communication internal connection line 4, but to the level conversion circuit 5. Connecting. In addition,
Since only the DR signal is a signal line that is also required in the terminal 7 side and the NCU modem control device 1, it is branched and connected to both the level conversion circuit 5 and the data communication internal connection line 4.

Therefore, the internal connection line 4 for data communication is N
The CU modem connection cable 3 is connected to the terminal 7 via the data communication terminal connection cable 6 without connecting the two signal lines of ER and CI. Furthermore, the terminal 7 and NC
The connection with the U-modem control device 1 is made by providing a network control command communication cable 8 for communicating a network control command / response. Network control command communication cable 8
Then, only the signal lines SD and RD are used, and these signal lines SD and RD are connected to the level conversion circuit 9 for level conversion.

When a call is made from the terminal 7 to the public telephone network for communication, a call command is transmitted to the NCU modem controller 1 through the network control command communication cable 8.

In the NCU modem controller 1, the SD signal in the network control command communication cable 8 is received by the network control command / response transmission / reception circuit 10 through the level conversion circuit 9, and the command / response information 11 is received by the network control information processing circuit 12. To inform.

In the network control information processing circuit 12, the ER signal ON information is NC as the NCU modem control input / output information 13.
The U-modem control signal generation circuit 14 is notified, the NCU modem control signal generation circuit 14 outputs the ON signal of ER1 to the level conversion circuit 5, and the level conversion circuit 5 turns ON of ER1.
After converting the signal to a signal level that can be recognized by the NCU modem,
It is output to the NCU modem 2 via the NCU modem connection cable 3.

The NCU modem 2 recognizes that the ER signal is ON and automatically issues a call to a predetermined telephone number. When the physical data communication link between the NCU modem 2 and the partner modem is established after the partner modem automatically receives the call, the NCU modem 2 turns on the DR signal to notify the NCU modem controller 1 that the data communication is possible. ..

In the NCU modem control device 1, the DR signal is passed to the network control information processing circuit 12 as NCU modem control information input / output information 13 through the level conversion circuit 5 and the NCU modem control signal generation circuit 14.

The network control information processing circuit 12 obtains the DR signal ON information after transmitting the calling command, and thus the acknowledge response is used as a response that the calling command from the terminal 7 functions correctly. The network control command / response transmission / reception circuit 10 is notified as the response information 11. The network control command transmission / reception circuit 10 outputs an acknowledge response using the RD1 signal, and after the level conversion circuit 9 converts the acknowledge response to a level that can be recognized by the terminal 7, the terminal 7 is called via the network control command communication cable 8. Communicate that was done correctly.

In the terminal 7, after the data communication line is definitely recognized in the public telephone line network, the communication software for the specific leased line is activated. Thus, the communication software for the specific leased line can be used in the public telephone line network.

Although not described in this embodiment, the NCU
When an incoming call is notified by the CI signal from the modem, the command and response are transmitted and received to and from the terminal 7 as in the case of the outgoing call, and after the automatic incoming call, the communication software for the specific leased line can be activated. Needless to say.

SD of the internal connection line 4 for data communication,
By monitoring the data line of the RD, it is possible to provide a non-communication monitoring timer function which is not generally required by the communication software for a specific leased line.

[0020]

According to the present invention, by adopting the configuration described above, the communication software for the specific leased line can be activated after setting the physical communication link in the public telephone line. This has the effect of expanding the software usage environment.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention.

[Explanation of symbols]

 1 NCU Modem Control Device 2 NCU Modem 3 NCU Modem Connection Cable 4 Data Communication Internal Connection Line 5 Level Conversion Circuit 6 Data Communication Terminal Connection Cable 7 Terminal 8 Network Control Command Communication Cable 9 Level Conversion Circuit 10 Network Control Command / Response Transmitter / receiver circuit 11 Command / response information 12 Network control information processing circuit 13 NCU modem control input / output information 14 NCU modem control signal generation circuit

Claims (1)

[Claims] 1. A public telephone line NCU capable of performing network control such as automatic call origination, incoming call detection, carrier signal detection, etc. by specific signal line control of RS232C (V.24) standard.
It is located between the modem and the terminal and has a channel for sending and receiving public line automatic call control commands separately from the data communication channel, and obtains the network control command from the network control command / response communication interface circuit. An NCU modem control device for controlling the input / output circuit for controlling the specific signal line.