JP3706311B2 - Communications system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a terminal network control device of a communication system that performs data transmission with a center side device using a digital line such as ISDN.
[0002]
[Prior art]
In general, in a communication system, a telephone set and a meter are connected to a terminal network control unit (T-NCU), and connected to a host computer of a center side device through a communication line such as an ISDN line (digital line).
[0003]
There are two types of activation methods: a terminal call originated from the T-NCU and a center activation in which meter reading is performed from the center side via the center network control device as needed. Center activation is called no-ringing (NR) activation for analog lines and number display (ND) activation for digital lines depending on the type of communication line. In the case of ND activation, since a caller telephone number signal is sent to the T-NCU, it is necessary to check whether the device is a center side device or not by that number. Here, the caller telephone number signal is output by setting the number display to be used in the terminal adapter (TA) connected to the ISDN line.
[0004]
[Problems to be solved by the invention]
Even if the TA is set to output a caller telephone number signal, the setting may be canceled due to a user resetting itself or resetting due to a power failure. In that case, there is a problem that the caller telephone number signal is not output from the TA and the activation from the center side device cannot be received. Therefore, the person in charge had to go to the user's house and reset the TA.
[0005]
In view of the above, an object of the present invention is to provide a terminal network control device capable of resetting a TA from a center side device even when the TA is reset.
[0006]
[Means for Solving the Problems]
The problem solving means according to the present invention is such that an adapter is attached so as to be able to communicate with a terminal adapter used for connecting to a digital line, and an interface for connecting the adapter is provided. That is, since the communication protocol in the terminal adapter (TA) and the communication protocol in the terminal network control unit (T-NCU) are different, the communication between the two is relayed by the adapter. Therefore, the adapter has a function of performing conversion between the communication protocol for T-NCU and the communication protocol for TA.
[0007]
In order to start communication from the center-side device and perform communication, it must be set to notify the caller telephone number from the TA. When using a digital line, it is necessary to set the TA as described above when installing the T-NCU. At this time, if TA is initially set by a command from the center side device, the user is not burdened and can be set accurately.
[0008]
Therefore, when communication with the center side device is started by calling the terminal and setting data is sent from the center side device, the data is output to the adapter by the communication protocol for T-NCU. The adapter converts the communication protocol for T-NCU from the communication protocol for TA and outputs the data to TA. In this way, the initial setting of TA can be performed easily and reliably. The TA setting data is not limited to the caller telephone number notification setting, and may be for setting other functions of the TA.
[0009]
As a countermeasure when the setting is canceled due to a TA reset or the like, a detecting unit for detecting whether or not the TA setting has been changed and a reporting unit for notifying the center side device that the setting has been changed are provided. By notifying the center side device of this setting change, similarly, resetting can be performed based on a command from the center side device, or setting data can be stored and resetting can be performed using this data. It is also possible to do this.
[0010]
By the way, since there may be a case where the TA side device cannot be notified due to the TA setting change, if the setting data received first from the center side device is stored, this data is output to the TA through the adapter, thereby allowing the center side device to be notified. TA can be reset even if there is no command from the side device.
[0011]
In addition, when an adapter is not connected, data cannot be output through the adapter. Therefore, a connection detecting means for detecting whether or not the adapter is connected is provided. When it is detected that the adapter is not connected, the setting data is directly output to the TA using the PB signal to perform resetting. Like that.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of a communication system of the present invention is shown in FIG. The center side device comprising the host computer 1 and the center network control device 2 and the T-NCU 3 are connected by a digital line 4 such as ISDN. Each network control device 2, 3 is connected to the digital line 4 with TA 5 and a line terminator ( DSU) 6 or DSU built-in TA7. The T-NCU 3 is connected to a telephone 8 and a meter 9, and contact devices such as sensors. In the figure, 10 is a center-side switching center and 11 is a terminal-side switching center.
[0013]
In response to a command from the host computer 1, the center network control device 2 dials the center side switching center 10 via the center side DSU built-in TA 7. The dialed destination number is transmitted to the terminal-side switching center 11, and the switching center 11 calls the T-NCU 3 via the terminal-side DSU 6 and TA5. At the time of this call, TA5 sends a pre-ringer signal to convey the caller telephone number.
[0014]
As shown in FIG. 2, the waveform of the pre-ringer signal appears at a cycle of 0.5 seconds after the polar reaction signal. In response to this pre-ringer signal, the T-NCU 3 loops as a primary response. Then, since a caller telephone number signal is transmitted from TA5, T-NCU3 receives it. Then, it is confirmed whether the caller telephone number matches the telephone number of the center side device. If it is not a call from the center side device, the caller phone number is connected to the telephone 8, and the ringer signal sent from the TA 5 is sent next. The telephone 8 rings. When the call is from the center side device, data transmission is performed with the center side device with the telephone 8 disconnected from the line 4.
[0015]
FIG. 3 shows the configuration of the T-NCU 3. The T-NCU 3 includes an anti-polarity detection circuit 20, a dial transmission circuit 21, a PB signal transmission circuit 22, a modem transmission circuit 23, a ringer detection circuit 24, a PB signal reception circuit 25, a modem reception circuit 26, a switching unit 27, an off-hook detection unit. 28, a CPU 29 having a microcomputer for controlling the line block A, an EEPROM 30 for storing data, and a power supply unit 31.
[0016]
The line block A is connected to the analog port of TA5 by a communication cable such as a modular cable, and the telephone 8 is connected to the switching unit 27 via a connector. A meter interface 32 for connecting the meter 9 is also provided.
[0017]
The T-NCU 3 includes an adapter 33 for relaying communication with the TA 5, and includes an adapter interface 34 for connecting the adapter 33. As shown in FIG. 4, the adapter 33 includes a T-NCU interface 40, a TA interface 41, a CPU 42 that converts signals received from the interfaces 40, 41 into a signal form on the other side, and a power supply unit 43. It consists of and. The T-NCU interface 40 and the adapter interface 34 of the adapter 33 are connected via a communication cable such as a modular cable, and the TA interface 41 and the TA5 serial port are connected via an RS232C cable.
[0018]
That is, in T-NCU3, data is handled in a message format according to a message protocol and communicates with the meter 9 or the center side device. In TA5, a personal computer is formatted according to a RS232C protocol different from the above protocol. It communicates with external devices such as. Thus, data cannot be transmitted as it is between the T-NCU 3 and the TA 5 due to the difference in the respective communication protocols. Therefore, the adapter 33 enables data transmission by converting both communication protocols.
[0019]
The specific operation of the adapter 33 will be described with reference to the flowchart of FIG. First, when the T-NCU 3 is newly installed, the setting device connected to the meter interface 32 downloads setting data necessary for the operation of the T-NCU 3 from the center side device. Minimum contents such as the ID of the T-NCU 3 are set (step 1). Next, the T-NCU 3 calls the center side device (step 2).
[0020]
The center side device confirms that the ID is the T-NCU 3 and writes the setting data to the T-NCU 3 (step 3). Further, a command for setting TA5 is transmitted and received by the T-NCU 3 (step 4). Note that when the initial setting is made, the adapter 33 is always connected.
[0021]
Receiving the command, the T-NCU 3 stores the setting command in the EEPROM 30 through the CPU 29 (step 5). Thereafter, the setting command is output to the adapter 33 through the adapter interface 34 by the message protocol (step 6).
[0022]
The adapter 33 receives the setting command formatted by the telegram protocol from the T-NCU interface 40 (step 7). The CPU 42 converts the received setting command based on the telegram protocol into a TA format based on the RS232C protocol (step 8). And it outputs to TA5 through TA interface 41 (step 9).
[0023]
When TA5 receives a setting command through the serial port, TA5 is set to a mode for outputting a caller telephone number. Thereby, the initial setting of TA5 is completed.
[0024]
Next, a case where the user changes the setting of TA5 after setting will be described based on the flowchart of FIG. At this time, it is unknown whether the adapter 33 is connected.
[0025]
Originally, it is a sequence in which a caller telephone number signal is transmitted from the analog port of TA5, following the pre-ringer signal of 0.5 second on and 0.5 second off shown in FIG. . However, if the caller telephone number signal does not come, the T-NCU 3 first measures the period of the pre-ringer signal (step 11). It is checked whether the cycle is within a certain range, for example, 600 msec or more and 1500 msec or less (steps 12 and 13). If it is within this range, it is determined that the setting is normal, and the next caller telephone number signal is read (step 15).
[0026]
If the cycle is out of the range, it is checked whether it has occurred twice consecutively (step 14). If it is only once, an abnormality may have occurred due to noise or the like, and the setting has not changed, so the caller telephone number signal is read (step 15). If it continues twice, it is determined that the setting of TA5 has changed.
[0027]
As described above, the T-NCU 3 can detect whether the setting of the TA 5 has been changed by the function of detecting whether or not the signal output from the TA 5 has a specified period.
[0028]
When the T-NCU 3 detects that the setting of TA5 has changed, it makes a call to the center side device (step 16). When the center side device receives a notification that the setting of TA5 is changed from T-NCU3, the center side device sends a setting command to reset TA5, which is received by T-NCU3 (step 17).
[0029]
Thereafter, whether or not the adapter 33 is connected is checked by a procedure described later (step 18). If connected, TA5 is reset by the same procedure as in the initial setting (step 19). If not connected, the center 33 is informed that the adapter 33 is not connected (step 20). Then, it goes on-hook once to release the line (step 21). Then, after waiting for a certain time (step 22), the loop is repeated (step 23).
[0030]
Then, the TA setting command stored in the EEPROM 30 is directly output to the TA 5 as a PB signal (step 24). Thereby, TA5 can be reset. The TA can be set by a PB signal from the telephone.
[0031]
By the way, there is a case where communication with the center side apparatus cannot be performed although an attempt is made to notify the center side apparatus. In that case, without communication with the center side device, the T-NCU 3 automatically resets the TA5 by either outputting the setting command through the adapter 33 or outputting the setting command by the PB signal. You may make it do.
[0032]
Here, a method for detecting whether or not the adapter 33 is connected to the T-NCU 3 will be described. As shown in FIG. 7, first, the T-NCU 3 outputs a connection confirmation command CHCON to the adapter 33 (step 31). After sending, in order to measure time, a certain time, for example, 2 seconds is set in the timer, and counting is started (step 32). It is confirmed whether or not there is a response from the adapter 33 within this fixed time (step 33). If there is a response, it is determined that the adapter 33 is connected (step 35). If there is no response, a timer timeout is detected (step 34), and it is determined that the adapter 33 is not connected (step 36). Therefore, even if another device is mistakenly connected to the adapter interface 34, there is no response, so that a connection error can be detected.
[0033]
Next, a method for reading the contents set in TA5 from the T-NCU 3 will be described. As shown in the flowchart of FIG. 8, first, the T-NCU 3 outputs a read command to the adapter 33 using a telegram protocol (step 41). In the adapter 33, the CPU 42 converts this telegram protocol into the RS232C protocol (step 42), and outputs the command to the TA 5 via the TA interface 41 (step 43).
[0034]
When TA5 receives the read command, TA5 outputs the data to the adapter 33 from the serial port by RS232C protocol as a response (step 44). The adapter 33 receives data via the TA interface 41 (step 45). The CPU 42 converts the RS232C protocol into a telegram protocol (step 46). The data is output to the T-NCU 3 via the T-NCU interface 40 (step 47). The T-NCU 3 transmits the received data to the center side device as required by a terminal call. Thereby, the setting content of TA5 can be easily read even from the center side device.
[0035]
A method for converting the telegram protocol to the 232C protocol in the adapter 33 will be described. As shown in FIG. 9, the message format according to the message protocol is composed of mark + STX + data part + ETX + BCC + space, the speed is 200 or 300 baud, and the character is JIS7. As shown in FIG. 10, the format according to RS232C is composed of an A + T + data portion after a mark and a mark at the end.
[0036]
As a conversion procedure, as shown in FIG. 11, if a mark is first received, it is considered that a message starts, and preparation is made to wait for reception of STX (step 51). Next, reception of one character in the data portion is started (step 52) and compared with ETX (step 53). If not ETX, the data is stored in a buffer in the CPU 29 (step 54). If ETX is received, the process proceeds to step 55, where BCC is received. Further, the BCC of the received data is calculated (step 56). The BCC is compared with the BCC of the received data (step 57). If the BCCs do not match, error processing in step 58 is performed. If the BCCs match, it waits for space reception (step 59).
[0037]
When the space is received, “A” and “T” data are added before the received data (step 60). This data is sent to the TA5 serial port with a specification of speed 9600 baud or more, 8 bits, stop bit = 1, and XON / XOFF (step 61). In this way, the command from the T-NCU 3 is sent to TA 5 after protocol conversion.
[0038]
The conversion from the RS232C protocol to the telegram protocol is the reverse operation. That is, STX, ETX, and BCC are added to the data following the AT received by the RS232C protocol, and the data is sent out at 200 or 300 baud and JIS7 between the marks and spaces.
[0039]
In addition, this invention is not limited to the said embodiment, Of course, many corrections and changes can be added to the said embodiment within the scope of the present invention. The adapter may be connected to the USB port of the TA by a USB cable. Even in this case, protocol conversion is performed in the same manner.
[0040]
In general, the T-NCU is often installed outdoors, the TA is installed indoors, and the adapter is also installed near the TA. For this reason, the T-NCU and the TA may be far apart, and the cable wiring becomes complicated. Therefore, using a wireless TA, the T-NCU is connected to the TA slave unit via a communication cable, and the adapter is connected to the TA master unit via an RS232C cable. Then, a communication circuit that performs wireless communication with the TA slave unit may be provided in the adapter, and a setting command may be transmitted from the T-NCU to the adapter via the TA slave unit.
[0041]
【The invention's effect】
As is apparent from the above description, according to the present invention, the initial setting and resetting of the TA can be automatically performed by outputting the command from the center side device to the TA through the adapter. Therefore, when a situation that should be reset due to an inadvertent reset, etc. occurs, it is possible to set it without the person in charge having to ask, and it is possible to prevent the communication from being started by the center side device being disabled, and the reliability of the communication system Can increase the sex.
[0042]
And if T-NCU detects TA setting change and reports to the center side device, if TA is reset immediately, the period during which communication from the center side device is disabled can be shortened. Data transmission such as meter reading can be performed reliably.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram of a communication system according to an embodiment of the present invention. FIG. 2 is a diagram showing signal waveforms transmitted from a digital line. FIG. 3 is a configuration diagram of a terminal network control device. [Fig.5] Flowchart for initial setting of terminal adapter [Fig.6] Flowchart for resetting terminal adapter [Fig.7] Flowchart for detecting adapter connection [Fig.8] Setting of terminal adapter Flowchart when reading contents [FIG. 9] Message format according to message protocol [FIG. 10] Format according to RS232C protocol [FIG. 11] Flowchart showing conversion procedure of communication protocol [Explanation of symbols]
3 Terminal network controller 4 Digital line 5 Terminal adapter 8 Telephone 9 Meter 33 Adapter 34 Adapter interface

Claims (7)

  A terminal network control device is connected to a digital line via a terminal adapter, and is a communication system for transmitting data between the terminal network control device and a center side device through the terminal adapter, the terminal adapter and the terminal network control An adapter that converts between a communication protocol for a terminal network control device and a communication protocol for a terminal adapter is connected between the devices, and the center side device sets a terminal adapter by a call from the terminal network control device. Data is transmitted to the terminal network controller, the terminal network controller outputs the setting data to the adapter, and the adapter converts the setting data according to a communication protocol for the terminal adapter. Output to the terminal adapter. System.   The terminal network control device has detection means for detecting presence / absence of a setting change of the terminal adapter, and notification means for notifying the center side device when the setting is changed, the center side device responding to the notification 2. The communication system according to claim 1, wherein setting data is transmitted to the terminal network control device for resetting.   The terminal network control device stores storage means for storing terminal adapter setting data, and if it cannot report to the center side device when it detects a setting change of the terminal adapter, the terminal network control device The communication system according to claim 2, further comprising means for setting an adapter.   4. The communication system according to claim 3, wherein the terminal network control device has resetting means for outputting the stored setting data to the adapter.   4. The communication system according to claim 3, wherein the terminal network control device has setting means for outputting the stored setting data directly to the terminal adapter using a PB signal.   The terminal network control device includes: a connection detecting unit that detects whether or not an adapter is connected; a setting unit that directly outputs setting data to the terminal adapter using a PB signal when the adapter is not connected; 3. The communication system according to claim 2, further comprising resetting means for outputting the setting data to the adapter when an adapter is connected.   The terminal network control device has storage means for storing setting data, and reporting means for reporting to the center side device that the adapter is not connected, and the terminal network control device connects the line after the notification. 7. The communication system according to claim 6, wherein after the release, the stored setting data is output to the terminal adapter using a PB signal.

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