JP4140972B2 - Selective automatic call method - Google Patents

Description

  The present invention relates to a selective automatic incoming call method such as automatic meter reading using a telephone line, remote control, notification, voice notification, answering machine and FAX.

  The network control device is a device that is connected between a telephone line and one or more terminal devices, and switches the connection between the telephone line and the terminal device. The network control device is connected to the central processing center via a telephone line, and is used in a system for automatically performing communication between the central processing center and the meter-reading meter terminal.

  Conventionally, a system using a network control device for selective automatic incoming call of a terminal device has an automatic meter reading system for automatically reading and controlling a meter meter in a customer's house.

  FIG. 18 is a configuration diagram of a conventional automatic meter reading system. The automatic meter reading system comprises a customer house 1 to be metered and an automatic meter reading center 2 connected to the customer house 1 via a telephone line 4. The customer's house 1 includes a network control device 11 connected to the telephone line 4, a terminal device 12 and a meter-reading meter 13 connected to the network control device 11. The terminal device 12 is, for example, a telephone or a FAX, and the meter-reading meter 13 is, for example, an electricity, gas, or water meter. The automatic meter reading center can automatically provide a service for acquiring a meter reading value of a meter meter or notifying an alarm. For example, when the meter-reading meter 13 is a gas meter, the use state of gas can be confirmed or the gas shut-off valve can be closed.

  Japanese Laid-Open Patent Application No. 6-62132 and Japanese Patent Application No. 2-212895 disclose a method (automatic incoming call method) for switching and connecting the telephone line 4 and one of the telephone set 12 and the meter-reading meter 13 to such a network control device 11. There is a disclosed ringing communication method. The ringing communication method is to read and control the meter-reading meter 13 in the customer's house 1 by calling from the automatic meter-reading center 2 without using the no-ringing service and F-net service provided by the communication carrier.

  In order to realize this ringing communication method, the conventional network control device 11 has an on / off hook detection circuit 111 for detecting on-hook and off-hook of the connected terminal device 12.

  FIG. 19 is an operation flowchart of the network control apparatus in the conventional ringing communication system. Hereinafter, it will be described along the flow.

  In this flowchart, the flow starts in response to a call from the automatic meter reading center 2 (step 201). First, since the network control device 11 connects the telephone line 4 and the telephone set 12, ringing from the telephone line 4 is transmitted to the telephone set 12 as it is and rings (step 202).

  Next, the on / off hook detection circuit 111 of the network control device 11 enters a waiting state (step 203) in order to detect the off hook of the telephone set 12. When a person in the customer's home goes off-hook the telephone set 12, the on-off hook detection circuit 111 detects the off-hook (step 204).

  Next, since the telephone line 12 and the telephone set 12 are connected, the automatic meter reading center 11 notifies the telephone set 12 of a message that meter reading should be performed from now on and that the telephone set 12 should be on-hooked ( Step 205). The message is, for example, “Here is Tokyo Gas. I called you to read the gas meter. Please take down the phone as it is.”

  Next, the on / off hook detection circuit 111 of the network control device 11 enters a waiting state (step 206) in order to detect the on-hook of the telephone set 12. Then, the person who has off-hooked the telephone 102 in accordance with the above-described message puts the telephone 12 on-hook. Then, the on / off hook detection circuit 111 detects the on-hook (step 207).

  Next, the network control device 11 switches so that the telephone line 4 is connected to the meter-reading meter 13 (step 208).

  Finally, the automatic meter reading center 11 and the meter meter 13 are connected via the telephone line 4 and can communicate with each other.

  However, in the conventional automatic meter reading system, in order for the automatic meter reading center to communicate with the meter meter, it is necessary to turn on / off the telephone connected to the network connection device. There was a problem that had to be done. In addition, if there was no person, the telephone had to automatically perform an on / off hook operation upon an incoming call.

  Further, the no-ringing service and the F-net service have a problem that they do not operate when the exchange and the terminal adapter for ISDN do not support such a service. In Japanese Patent Application No. 2-212895, it is possible to receive a call when there is no person in the consumer, but this is invalid when a telephone which is a subsequent consumer terminal apparatus automatically receives a call.

  Therefore, an object of the present invention is to solve this problem, and without requiring the presence of a person at the customer's home, etc., a terminal device such as a telephone and a meter meter such as a meter meter can be used for the telephone line. It is an object of the present invention to provide a selective automatic incoming call method for automatically switching to a specific remote control device.

In order to solve the above problems, a selective automatic incoming call method according to an aspect of the present invention includes a network control device (hereinafter also referred to as NCU) connected to a telephone line and a plurality of terminal devices connected thereto. A selective automatic incoming call method in a facility; a specific terminal having a specific pattern composed of a combination of element patterns of ringing a specific number of times after being ringed from a specific calling terminal and calling again after a predetermined time When a call signal to the device (automatic call receiving terminal) is sent, the NCU detects the call signal, switches the network to the specific terminal device (automatic call receiving terminal), and sends the calling terminal and the specific terminal device (automatic call receiving terminal). ), A specific calling terminal terminates the call after a certain time after sending the call signal, and forms a specific pattern, and the communication equipment is connected to a plurality of telephone lines connected in series. An NCU is provided, and a different specific pattern is set for each of the plurality of NCUs .

When each of the plurality of NCUs detects a specific pattern set in the NCU, the NCU switches the network to a specific terminal device (automatic incoming terminal) connected to the NCU, and transmits the transmission terminal and the specific terminal. Communication is performed with (automatic receiving terminal). On the other hand, when one or more element patterns in the combination of element patterns constituting the specific pattern are different from the element patterns included in the combination of the specific patterns in the paging signal, the NCU sends the specific calling terminal to the specific calling terminal. Callback is a feature.

  According to the present invention, a selective automatic incoming call operation can be performed on a plurality of communication terminal devices at a customer's house using a specific calling pattern corresponding to the communication terminal device, without being limited to a center that has made a no-ringing contract. It becomes possible. For this reason, it is possible to automatically and automatically receive calls regardless of whether there are people in the consumer.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In particular, an automatic meter reading system will be described as an example.

  FIG. 1 is a configuration diagram of an automatic meter reading system using a telephone network according to the present invention. In addition to the conventional on / off hook detection means 111, the network control apparatus in the system further includes a call detection means 112, a network control portion 113, and a selective incoming call terminal 114. The call detecting means 112 detects the number of calls or the call interval time in order to detect a specific call pattern.

  In order to communicate with the meter-reading meter 13, the automatic meter-reading center 11 must repeat calling and stopping so as to transmit the specified calling pattern corresponding to the meter-reading meter 13 from the telephone exchange to the network control device 11. Don't be.

  FIG. 2 is an example of a calling pattern. For example, a call is made from the automatic meter reading center 2 to the network control device 11 of the customer's house 1, and the call is stopped after the call rings once at the customer's house. Next, the call is made again in 25 seconds from the start of the first ringing, and the ringing is stopped after the ringing is made once. Further, the pattern is such that a call is made again in 25 seconds from the start of the second ringing.

  On the other hand, the network control device 11 confirms that the call is stopped after the incoming call is received and the call rings once at the customer's house. Next, the user rings again within 25 ± 5 seconds from the start of the first ringing, and confirms that the ringing is stopped after ringing once. Further, it is confirmed that the incoming call is received again within 25 ± 5 seconds from the start of the second ringing, and a specific calling pattern is detected.

  The specific method of stopping the call after ringing once in the customer's house is to stop the call within a certain time (for example, 3 seconds) after sending the selection signal on the calling side, The customer rings only once.

  Further, for example, if the telephone exchange 3 used in the present invention is constructed with IN equipment, it is identified that the telephone exchange is a call from the automatic meter reading center, and a specific calling pattern is set. Can be sent out.

  FIG. 3 is a schematic configuration diagram of a telephone exchange system constructed with IN equipment. The telephone switching system has a service control station that controls a large number of telephone switches integrated by a common line signal network. Thus, by registering service control information for each user in a database or the like in advance, it is possible to identify a call from the automatic meter reading center and send a specific calling pattern. Therefore, if a plurality of terminal devices are connected to the network control device 11 of the customer's home 1, a plurality of calling patterns corresponding to the terminal devices can be transmitted while being selected from the telephone exchange 3.

  As a method for identifying that the service control station is a call from a specific caller, for example, there is a method in which a specific caller adds a specific selection signal to a normal selection signal to make a call. Or the specific caller may have registered the caller number in the service control station in advance.

  FIG. 4 is a block diagram of an automatic meter reading system using an ISDN network according to the present invention.

  Compared to the configuration diagram of FIG. 1, FIG. 4 further includes a DSU (Digital Service Unit) 14 connected to the ISDN line 4 and a TA connected to the DSU in the customer's house 1. (Terminal Adapter) 15. The network control device 11 is connected to the TA port. The analog terminal device 16 such as a telephone may be directly connected to the TA port, and the digital terminal device 17 is directly connected to the DSU 14.

  When one or more terminal devices connected to the DSU and TA make a call from the subaddress of the port corresponding to the terminal device when the automatic meter-reading center makes a call from the ISDN line, each terminal device is called. It can be called. Therefore, when the automatic meter reading center makes a call at the subaddress of the port to which the network control device 11 is connected, the network control device can be called.

  However, if the TA15 subaddress is changed or the connection is changed to a port without a subaddress, the network controller may not receive a call even if a specific caller makes a call with a subaddress. is there. In this case, when retrying after the first incoming failure, it is possible to send a selection signal without a sub-address and forcibly cause all terminal devices to ring and call the network control device. .

FIG. 5 is a configuration diagram in which a plurality of network control devices 11 are connected in series to the telephone line 4 according to the present invention.

  Two network control devices 11 and 18 are connected in series to the customer's house 1, and the network control device has a terminal device 12 such as a telephone and terminal devices 13 and 19 such as a meter-reading meter. ing. The network control devices 11 and 18 have on / off hook detection means 111 and 181 respectively, and individually correspond to different call patterns.

  For example, the network control device 11 stops calling after the ringing signal rings once, stops ringing after the ringing signal rings once again within 25 seconds ± 5 seconds from the start of the first ringing, and the second ringing. The call pattern is such that the call signal is sent again within 25 seconds ± 5 seconds from the start. On the other hand, the network control device 18 stops the call after the ringing signal rings once, stops the ringing after the ringing signal rings once again within 35 seconds ± 5 seconds from the start of the first ringing, and starts the second ringing. In this pattern, the call signal is sent again within 35 seconds ± 5 seconds.

  In this way, since a specific calling pattern is preset for each of the plurality of network control devices, it becomes possible to selectively call one of the network control devices.

As another embodiment , a plurality of terminal devices (meter reading meters 13 and 19 shown in FIG. 5 ) may be connected in parallel to the network control device 11 (not shown) . A different specific pattern is set for each terminal device, and the connected terminal device can be selectively called by the different specific calling pattern. In this case, a single network control device can handle two meter reading meters.

  6 and 7 are flowcharts of the network control apparatus of the present invention in the ring prefetch ring response. Hereinafter, it demonstrates along a flow.

  The call detection means 112 of the network control device 1 is initially in a ringing detection standby state (step 801). When ringing occurs (step 802), ringing is detected (step 803), and the time when the ringing occurs is stored. Then, the number of ringing is counted (step 804).

  Next, it is determined whether or not the count number is a part of a specific calling pattern, that is, a predetermined number of times (step 805). If the ringing does not stop after a predetermined number of times, it is determined that the incoming call is from a third party (step 820). If the ringing stops less than the predetermined number of times, there is a possibility of a specific calling pattern, so that a shift is made to the self-off-hook standby state (step 806).

In the self-off-hook standby state (step 806), it is in a standby state to detect ringing again. When a ringing occurs again, it is determined whether T ₁ = 25 ± 5 seconds or less from the first ringing in that state (step 807). Unless T ₁ within, determines that the incoming call from the third party (step 820), if it is within T _1, counts the ringing number since there is a possibility a specific pattern (Step 808).

  Next, it is determined whether or not the count number is a predetermined number (step 809). If the ringing does not stop after a predetermined number of times, it is determined that the incoming call is from a third party (step 820). If the ringing stops less than the predetermined number of times, there is a possibility of a specific pattern, so the self-off-hook standby state (step 810) is continued again.

It is in a standby state to detect the ringing again, again, when the ringing occurs, it determines whether within T ₁ from generation of the first ringing (step 811). Unless T ₁ within, determines that the incoming call from the third party (step 820), if it is within T _1, it is determined that the specific calling patterns, and off-hook, the signal waiting from the caller is a center A state is reached (step 812). Note that the ringing at intervals of T ₁ may not be one time.

  If the signal from the center is not received (step 814) and a predetermined time has passed (step 817), it is determined that the incoming call is from a third party (step 818), and the on-hook state is maintained without sound (step 819). ).

  When a signal from the center is received (steps 813 and 814), the network control device performs switching control so that the telephone line and the meter-reading meter are connected, and communication between the center and the meter-reading meter is established ( Step 815). When the communication between the center and the meter-reading meter is normally completed (step 816), a shift is made to the initial state. The communication time between the center and the meter-reading meter is managed by a timer, and when a predetermined time has passed (step 821), the process is terminated and the state shifts to the initial state.

  8 and 9 are flowcharts of the network control apparatus according to the present invention in the ring preemptive ringing response. Below, FIG. 8 and FIG. 9 will be compared with FIG. 6 and FIG. 7 described above, and only the differences due to silence will be described.

  Comparing Steps 901 to 921 in FIGS. 8 and 9 with Steps 801 to 821 in FIGS. 6 and 7, portions other than Steps 905 and 909 are exactly the same. In order to make no ringing, if the ringing of steps 905 and 909 does not stop for less than a predetermined number of times, it is determined that the third party has received an incoming call. At this time, the on / off hook detection means 111 operates. Is different.

  If ringing does not stop after less than the predetermined number of times, the terminal is connected to a communication terminal device such as a subsequent telephone (step 930). Then, it is detected whether or not the telephone is off-hook (step 931). If the call is canceled without being off-hook (step 936), the process is terminated, and the process shifts to the initial state.

  If the telephone goes off-hook (step 931), on-hook monitoring of the subsequent telephone is started (step 932). When the latter telephone set is on-hook (step 933), the telephone line is disconnected from the telephone, and the on-hook monitoring of the latter telephone set is terminated (step 934). Next, off-hook monitoring at the subsequent stage is started again, and the process is terminated (step 935).

  10 and 11 are flowcharts on the center side with respect to the flowchart of the network control apparatus described above. Below, it demonstrates along a flow.

First, when a communication request to the meter-reading meter is generated from the control part of the center (step 1001), the call is dialed to the call destination (step 1002) and called a predetermined number of times of ringing (step 1003). At this time, even if the telephone of the customer's house and the network control device go off-hook, the center goes on-hook and does not communicate. According to a specific calling pattern, when T ₀ = 25 seconds have elapsed from the first dialing, dialing is performed again (step 1004). Then, it is called for a predetermined number of times of ringing (step 1005).

Again, when T _{0 has} elapsed since the second dialing, dialing is performed again (step 1006). At this time, it is detected whether or not the network control device at the customer's house is off-hook (step 1007).

  If it does not go off-hook even after a predetermined time has elapsed (step 1008), it is determined that the incoming sequence has failed (step 1014), and on-hook (step 1017) to end. At this time, if the retry is a predetermined number of times or more (step 1018), communication failure is displayed (step 1019), and if it is less than the predetermined number of times, a call is made to the customer's house again.

  When the network control device at the customer's home goes off-hook (step 1007), the network control device is called by the modem and a response from the network control device is waited (step 1009).

  If the response from the network control device is not notified even after a predetermined time has elapsed (step 1011), it is assumed that the telephone connected to the network control device is off-hook (step 1013), and the talkie is The process is terminated without notification. The talkie here is a message such as "Here is Tokyo Gas. I called you to read the gas meter. Please do not pick up the phone the next time you call." It is. In this way, without being notified of the talkie, it goes on-hook (step 1017), and if the retry is a predetermined number of times or more (step 1018), it indicates that communication is not possible (step 1019) and ends.

  When a response from the network control apparatus is notified (step 1010), communication is performed between the network control apparatus and the center (step 1012). If the communication is normally completed (step 1015), it is on-hook (step 1016), shifts to the initial state, and ends. If the communication has not ended normally, it goes on-hook (step 1017), and if the retry is a predetermined number of times or more (step 1018), it indicates that communication is not possible (step 1019) and ends.

  If the number of retries is less than the predetermined number of times, a communication impossible retry request display is first performed (step 1020). Then, when 30 seconds or more have passed since the last call (step 1021), the call is made again. However, if an ISDN line is used and a call is made using a subaddress in the first call pattern transmission stage, a call is made without using the subaddress (step 1022). As a result, even if the sub-address of the network connection device to be connected has been changed, the call connection can be made.

  In another embodiment, if the network controller determines that some of the specific call pattern signals or one specific call pattern element is met, the network controller does not go off-hook and the call is complete. There is a means to call back to a specific caller. That is, the network control device stores the telephone number of the automatic meter reading center, or can call back by obtaining the telephone number from the connected communication terminal device.

  Even if all match a specific calling pattern, the network control device may call back without going off-hook. This is because, for example, if an attempt is made to exclude a pattern slightly deviating from a specific calling pattern, an important urgent communication is missed and the incoming call cannot be made. In order to prevent such an important communication from being overlooked and not receiving an incoming call, if the identification determination of the specific call pattern is loosened, there is a high risk that the network control device erroneously off-hooks a call from a third party.

  However, by performing the callback, there is no risk that the network control device off-hooks the third party's call by mistake, and the risk of missing important urgent communication can be eliminated at the same time.

  12 and 13 are flowcharts of the ringing callback. Hereinafter, it will be described along the flow.

  The call detection means 112 of the network control device 1 is initially in a ringing detection standby state (step 1101). When ringing occurs (step 1102), ringing is detected (step 1103) and the time when the ringing occurs is stored. Then, the number of rings is counted (step 1104).

  Next, it is determined whether or not the count is a part of a specific calling pattern for connecting the telephone line to the meter-reading meter, that is, a predetermined number of times (step 1105). If the ringing does not stop after a predetermined number of times, it is determined that the incoming call is from a third party (step 1126). When the ringing stops after less than the predetermined number of times, there is a possibility of a specific pattern, so that a shift is made to the callback waiting state (step 1106).

  In the callback waiting state (step 1106), it is in a waiting state to detect ringing again. When the ringing occurs again, it is determined whether it is within 25 ± 5 seconds from the first ringing (step 1107). If it is not within 25 ± 5 seconds, it is determined that the incoming call is from a third party (step 1126). If it is within 25 ± 5 seconds, there is a possibility of a specific pattern, so the number of ringing is counted (step 1108). ).

  Next, it is determined whether or not the count number is a predetermined number (step 1109). If the ringing does not stop after a predetermined number of times, it is determined that the incoming call is from a third party (step 1126). If the ringing stops after less than the predetermined number of times, there is a possibility of a specific pattern, so the callback waiting state (step 1110) is continued again.

  Next, it is determined whether it is within 25 ± 5 seconds from the occurrence of the second ringing (step 1111). If it is not within 25 ± 5 seconds, it is determined that the incoming call is from a third party (step 1126). If it is within 25 ± 5 seconds, there is a possibility of a specific pattern, so the number of ringing is counted (step 1112). ).

  Next, it is determined whether or not the count number is a predetermined number (step 1113). If the ringing does not stop after a predetermined number of times, it is determined that the incoming call is from a third party (step 1126). When ringing stops after less than the predetermined number of times, the second dial for callback is read from the meter-reading meter (step 1114).

  Next, it goes off-hook and dials the center with the read second dial (step 1115). Then, it is detected whether the center is off-hook (step 1116). If the center does not go off-hook even after a predetermined time has elapsed (step 1117), it is determined that the dial is wrong (step 1124), and if the retry is a predetermined number of times or more (step 1125), the processing is terminated. Shift to the initial state. If the predetermined number of retries has not been reached, the process waits for the center to go off-hook (step 1116).

  When the center goes off-hook for a call from the network control device (step 1116), the network control device sends a specific signal to the center (step 1118). The center responds to a specific signal from the network control device with a specific signal. When the specific signal is received (step 1119), communication is performed between the center and the network control device (step 1121). If the communication is normally completed (step 1122), the process is terminated and the process shifts to the initial state. If the communication has not been completed normally and a predetermined time has passed (step 1123), it is determined that the dialing is wrong (step 1124), and if the retry is a predetermined number of times or more (step 1125), the process is terminated. Shift to the initial state.

  FIG. 14 and FIG. 15 are flowcharts of the network control apparatus of the present invention in the ringless ringing callback. Below, FIG.14 and FIG.15 and FIG.12 and FIG.13 mentioned above are compared, and only the difference by making it silence is demonstrated.

  Comparing Steps 1201-1226 in FIGS. 14 and 15 with Steps 1101-1126 in FIGS. 12 and 13, the flowcharts other than Steps 1205 and 1209 are exactly the same. In order to make no ringing, if the ringing of steps 1205 and 1209 does not stop for less than a predetermined number of times, it is determined that the third party has received the call. At this time, the on / off hook detection means connected to the subsequent stage is It differs in that it works.

  Steps 1230 to 1236 in FIGS. 14 and 15 and steps 930 to 936 in FIGS. 8 and 9 are exactly the same flow.

  16 and 17 are flowcharts on the center side with respect to the flowchart of the network control apparatus that performs the callback described above. Below, it demonstrates along a flow.

  First, when a communication request to the meter-reading meter is generated from the control part of the center (step 1301), the call is dialed to the call destination (step 1302) and called a predetermined number of times of ringing (step 1303). At this time, even if the telephone of the customer's house and the network control device go off-hook, the center goes on-hook and does not communicate. According to a specific calling pattern, when 25 seconds have passed since the first dialing, dialing is performed again (step 1304). Then, a predetermined number of ringing is called (step 1305).

  Again, when 25 seconds have elapsed since the second dialing, dialing is performed again (step 1306), and a predetermined number of ringing is called (step 1307).

  Next, it waits for a callback from the network control device (step 1308). If the network controller has called back (step 1317), the network controller waits for a call from the modem (step 1309). If the callback is not made even after a predetermined time has elapsed (step 1323), it is estimated that the incoming sequence has failed (step 1314), and the system goes on-hook to end the process. At this time, if the retry is a predetermined number of times or more (step 1318), communication failure is displayed (step 1319), and if it is within the number of times, a call is made to the customer's house again.

  While waiting for a modem call from the network controller (step 1309), if a response is not notified even after a predetermined time has passed (step 1311), it is determined that the incoming call is from a third party. (Step 1313) and again waits for a callback from the network control device (Step 1308). When the response is notified (step 1310), the network control device switches so that the telephone line and the meter-reading meter are connected, and communication is established between the center and the meter-reading meter (step 1312). If the communication is normally completed (step 1315), the process is terminated off-hook (step 1316), and the process shifts to the initial state.

  In the above description, the automatic meter reading system has been described as an example of the system using the network control device of the present invention. However, the technical idea and the viewpoint of the present invention can be applied to various selective automatic call control devices. Various changes, modifications, and omissions in the range can be easily made by those skilled in the art. Therefore, the above description is merely an example, and is not intended to be limited. The present invention is limited only as limited by the following claims and their equivalents.

It is a block diagram of the automatic meter-reading system which has the network control apparatus connected to the telephone line by this invention. FIG. 3 is a schematic diagram of a calling pattern according to the present invention. It is a block diagram of the telephone exchange system which has IN equipment. It is a block diagram of the automatic meter-reading system which has the network control apparatus connected to the ISDN line by this invention. It is a block diagram of the automatic meter-reading system which connected the network connection apparatus by this invention in series. It is a front | former stage of the flowchart of the ring prefetch ringing response of the network control apparatus by this invention. It is a back | latter stage of the flowchart of the ring prefetch ringing response of the network control apparatus by this invention. It is a front | former stage of the flowchart of the ring preemption ringing response of the network control apparatus by this invention. It is a back | latter stage of the flowchart of the ring prefetch ringing response of the network control apparatus by this invention. It is a front | former stage of the flowchart of the ring prefetch ringing / no ringing response of the automatic meter-reading center by this invention. It is a back | latter stage of the flowchart of the ring prefetch ringing / no ringing response of the automatic meter-reading center by this invention. It is a front | former stage of the flowchart of the ring ringing callback of the network control apparatus by this invention. It is a back | latter stage of the flowchart of the ring ringing callback of the network control apparatus by this invention. It is a front | former stage of the flowchart of the ring non-ringing callback of the network control apparatus by this invention. It is a back | latter stage of the flowchart of the ring non-ringing callback of the network control apparatus by this invention. It is a front | former stage of the flowchart of ring ringing / non-ringing callback of the automatic meter-reading center by this invention. It is a back | latter stage of the flowchart of the ring sounding / non-ringing callback of the automatic meter-reading center by this invention. It is a block diagram of the automatic meter-reading system using the conventional network control apparatus. It is a flowchart for automatic meter-reading using the conventional network control apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Consumer house 2 Automatic meter-reading center 3 Telephone exchange 4 Telephone line 5 ISDN exchange 6 ISDN line 11, 18 Network control device 12 Communication terminal device, Telephone 13, 19 Meter-reading meter 14 DSU
15 TA
16 Analog communication terminal device, telephone 17 Digital communication terminal device 111, 181 On / off hook detection means 112, 182 Call detection means

Claims (1)

A selective automatic incoming call method in a communication facility comprising a network control device (hereinafter also referred to as NCU) connected to a telephone line and a plurality of terminal devices connected thereto;
A ringing signal is sent to a specific terminal device (automatic call receiving device) having a specific pattern consisting of a combination of element patterns of ringing a specific number of times from a specific calling terminal and then calling again after a predetermined time. When sent, the NCU detects the call signal, switches the network to the specific terminal device (automatic incoming terminal), and performs communication between the transmitting terminal and the specific terminal device (automatic incoming terminal). I,
The specific calling terminal, constitute the specific pattern by ending the call after the call signal transmission after a predetermined time,
The communication facility includes a plurality of the NCUs connected in series to the telephone line;
Different specific patterns are set in each of the plurality of NCUs, and when each of the plurality of NCUs detects the specific pattern set in the NCU, the specific terminal device connected to the NCU ( The network is switched to an automatic receiving terminal), and communication is performed between the transmitting terminal and the specific terminal device (automatic receiving terminal),
In the paging signal, when one or more of the element patterns constituting the specific pattern are different from the element patterns included in the specific pattern combination, the NCU determines that the specific pattern is the specific pattern. A selective automatic incoming call method, characterized by calling back to the outgoing terminal.

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