JP3842263B2 - Button telephone device and key telephone main device - Google Patents

Description

  The present invention relates to a button telephone apparatus having a function of detecting disconnection of an analog line of a public network.

  A public network analog line is provided by a pair (two lines) of wiring. One of the two lines of the pair of wirings is called an L1 line and the other is called an L2 line, and the analog line is in a standby state. A battery (−48V) is supplied to the L1 line, and ground (earth) is supplied to the L2 line. When the incoming state is reached, the ground is supplied to the L1 line and the polarity in which the battery is supplied to the L2 line is reversed, and then a call signal is transmitted.

  The key telephone main unit that accommodates the analog line indicates that the analog line has changed from the standby state (L1 line: battery, L2 line: ground) to the polarity inversion state (L1 line: ground, L2 line: battery). Then, the incoming call is detected by detecting that the call signal (incoming call information) has been sent. In addition, when the polarity inversion state of the analog line is detected, outgoing / incoming collision prevention processing is performed to prohibit outgoing calls using the analog line and prevent collision between outgoing and incoming calls before a call signal is transmitted.

  Next, the configuration of an outside line circuit unit having a polarity detection circuit for detecting the polarity of an analog line will be described with reference to FIG. FIG. 5 is a block diagram showing details of the configuration of the external line circuit unit 13 provided in the key telephone main unit and accommodating the analog line of the public network.

  In FIG. 5, the external line circuit unit 13 includes an I / F (highway interface circuit) 131, a CODEC (codec circuit) 132, a 2-wire / 4-wire conversion unit 133, a transmission / reception circuit 134, and a polarity detection circuit 135. The polarity detection circuit 135 configured to include analog line terminals T11 and T12 and detects the polarity of the analog line monitors the polarity between the two analog lines (L1 line, L2 line).

  The external line circuit unit 13 having the polarity detection circuit 135 is used to monitor the polarity of the analog line. When the polarity inversion state (L1 line: ground, L2 line: battery) continues for a predetermined time, this polarity is set to the standby state. The polarity of the analog line is memorized and the polarity inversion detection function for detecting the change of the polarity of the analog line from the stored state is provided. A button telephone device having a function of enabling so-called nonpolar connection, which can be connected without any problem, has become common (see, for example, Patent Document 1).

  On the other hand, when the connected telephone line is disconnected (disconnected) in an emergency alarm device having a function of automatically reporting to the outside using a telephone line (corresponding to the analog line of the public network described above) There is an emergency alarm device having a function of automatically reporting to the outside a radio other than a telephone line as a relay means when detected. However, this emergency alarm device includes a line voltage detection circuit that detects a voltage between two analog lines as a telephone line disconnection detection means, unlike the above-described polarity detection circuit (for example, Patent Document 2). reference).

Recently, the necessity of an analog line has been recognized again due to the spread of ADSL, and a button telephone device having the same function as an emergency alarm device has been provided from the viewpoint of security. In disconnection detection, it is necessary to provide the above-described line voltage detection circuit, and a button telephone device incorporating such a disconnection detection function has a problem that it is more expensive than one without a disconnection detection function.
JP 2003-111115 A JP-A-6-133067

  The problem to be solved by the present invention is to realize a key telephone apparatus having an analog line disconnection detecting function at low cost.

In order to solve the above-mentioned problems, the present invention provides a key telephone main apparatus having a function of accommodating one or more analog lines and a plurality of extensions and being able to connect the analog lines with no polarity, and a plurality of terminals connected to the extensions. In the key telephone apparatus comprising the key telephone, the key telephone main unit is configured to detect incoming information from the analog line, detecting the polarity of the analog line, and detecting the normal polarity to detect the normal polarity. A polarity detection circuit that outputs information, detects reverse polarity and outputs reverse polarity information, and the polarity detection circuit when the polarity detection circuit is connected with the reverse polarity from the initial connection polarity of the analog line. wherein the circuit is the incoming call detecting means from detecting within the predetermined time period that the polarity information output is changed to the normal polarity information from the inverted polarity information does not detect incoming information analog A disconnection detecting means determines that the disconnection of the line, the cross line detection means includes a disconnection notification means for notifying the disconnection detection information determined to be the disconnection of the analog lines to the outside.

Further, the present invention provides the key telephone apparatus, wherein the key telephone has a function of displaying disconnection detection information when the disconnection detecting means of the key telephone main apparatus determines that the analog line is disconnected. It was .

Further, according to the present invention, in the above button telephone device, the key telephone main device has a function of displaying disconnection detection information when the disconnection detecting means determines that the analog line is disconnected.

  According to the present invention, a button telephone device with a disconnection detection function can be realized at low cost by using a polarity detection circuit without providing a dedicated line voltage detection circuit.

  Hereinafter, an embodiment of a button main device having a disconnection detection function according to the present invention will be described. In the following embodiments, a button telephone main apparatus and a wired button telephone connected to the button telephone main apparatus will be described as examples of the button telephone apparatus. However, the present invention is not limited to this. For example, a wireless button telephone can be used instead of a wired button telephone. Moreover, it may be implemented by a private branch exchange instead of the key telephone apparatus. In this case, the key telephone main apparatus in the specification is interpreted as a private branch exchange apparatus.

  FIG. 1 is a schematic diagram of the configuration of a key telephone main apparatus 10 having one or more external lines and a plurality of extensions constituting the key telephone apparatus according to the present invention. FIG. 2 is a schematic configuration diagram of the key telephone 20 connected to the extension constituting the key telephone device according to the present invention. FIG. 3 is a functional block diagram of the central control unit 11 of the present invention. FIG. 4 is a schematic flowchart of processing in each means in the central control unit 11 of the key telephone main device 10 of the present invention. FIG. 5 is a detailed configuration diagram of the outside line circuit unit 13 of the key telephone main device 10. FIG. 6 is a schematic circuit diagram of the polarity detection circuit 135 in the external line circuit unit 13 of the key telephone main device 10.

  First, the outline of the configuration of the key telephone main device 10 will be described with reference to FIG. The key telephone main device 10 includes a central control unit 11, a speech path switch unit 12, one or more external circuit units 13-1 to 13-n, a voice guidance transmission unit 14, and a plurality of extension circuits 15-1 to 15-1. 15-n, the memory | storage part 16, the disconnection indicator 17, the disconnection notification part 18, and the sensor detection part 19 are comprised. When the sensor detection unit 19 detects an intruder from the outside, for example, the key telephone main device 10 can function as an emergency alarm device that notifies the notification destination to that effect.

  The central control unit 11 analyzes and determines input information (including information from the key telephone) from each circuit of the key telephone main device 10, inputs / outputs information to / from the storage unit 16, and controls each circuit.

  The communication path switch unit 12 performs digital exchange processing (connection between external lines and internal lines, connection of voice guidance to external lines, etc.) in the key telephone main device 10.

  The external line circuit 13 (13-1 to 13-n) is an interface circuit connected to an analog line, and detects the polarity of the analog line, which is normal polarity information that is normal polarity or reverse polarity information that is reverse polarity. The polarity information is output.

  The voice guidance sending unit 14 detects a sensor operation by the sensor detection unit 19 and sends a voice guidance when making a notification via an external line. 1 to 13-n.

  The extension circuit unit 15 (15-1 to 15-n) is an interface circuit for communicating voice data and control data with the key telephones 20-1 to 20-n.

  In addition to the function as a normal storage unit, the storage unit 16 also stores a state of polarity of the analog line in a standby state, a report destination for reporting that the sensor has detected an abnormality at the time of sensor detection, and the like.

  The disconnection indicator 17 is provided at a location that is easily visible from the outside of the surface of the key telephone main device 10, and displays that the external line (analog line) is disconnected. Specifically, an LED display is used. When the key telephone main device 10 has a display unit such as an LCD (not shown), the disconnection indicator 17 may display a disconnection on the screen of the LCD display unit.

  The disconnection notification unit 18 includes a communication unit that is connected to an external device such as an information processing apparatus and notifies disconnection information. Specifically, RS-232C or USB is used. The external device connected to the disconnection notification unit 18 may report disconnection information to the report destination via communication means other than the analog line accommodated in the key telephone main device 10.

  The sensor detection unit 19 is connected to an external sensor and detects the function of the sensor. As types of sensors that can be connected, door opening / closing sensors, human body detection sensors, and the like are commercially available. When the sensor is a door open / close sensor or a human body detection sensor and is in a monitoring state, if the door is opened or closed or a human body is detected, the presence of an intruder is detected.

  Next, the outline of the configuration of the key telephone 20 will be described with reference to FIG. The key telephone 20 includes a control unit 21, a data transmission / reception circuit 22, a voice processing unit 23, a handset 24, a speaker 25, a dial key 26, an outside line key 27, a function key 28, and an LCD display 29. And a disconnection indicator 30. The disconnection indicator 30 may be provided as an independent element, or may be displayed on the screen of the LCD display 29 without being provided as an independent element.

  The control unit 21 analyzes and determines input information from each circuit in the key telephone 20, controls each circuit, and controls display information transmitted from the key telephone main device 10 via the data transmission / reception circuit 22.

  The data transmission / reception circuit 22 is connected to the extension circuits 15-1 to 15-n of the key telephone main device 10 and is an interface circuit for communicating voice data and control data.

  The voice processing unit 23 controls voice digital / analog conversion, analog / digital conversion, call path switching with the handset 24, the speaker 25, and the like in the key telephone 20 and volume.

  The handset 24 is a handset for performing transmission and reception during a general call.

  The speaker 25 is used for sending a ring tone for an external line or an internal line, or for outputting a loud voice reception by the speaker.

  The dial key 26 is used for inputting a telephone number. It is also used as input means for various settings.

  The outside line key 27 is a button for selecting an outside line to be used from a plurality of outside lines.

  The function key 28 is a button used for holding generally used in a button telephone apparatus, voice reception, transition to various settings, and the like.

  The LCD display 29 displays the other party's telephone number when calling from the key telephone to the outside line, the call time display, the caller telephone number at the time of incoming call, and the like.

  The disconnection indicator 30 is provided at a location that is easy to see from the outside of the surface of the key telephone 20, and displays that the external line (analog line) has been disconnected based on the disconnection display information transmitted from the key telephone main device 10. Specifically, an LED display is used. Further, it is also possible to display the disconnection on the LCD display 29 without providing a dedicated display.

  Next, a detailed configuration of the external line circuit unit 13 of the key telephone main device 10 will be described with reference to FIG. As described above, the external line circuit unit 13 includes the I / F 131, the CODEC 132, the 2-wire / 4-line conversion unit 133, the transmission / reception circuit 134, the polarity detection circuit 135, and the analog line terminals T11 and T12. Configured.

  The I / F 131 is an interface circuit connected to the speech path switch unit 12 via a highway.

  The CODEC 132 converts the analog signal from the 2-line / 4-line conversion unit 133 into a digital signal and sends it to the I / F 131. Also, the CODEC 132 converts the digital signal from the I / F 131 into an analog signal and converts it into a 2-line / 4-line. The data is sent to the conversion unit 133. The CODEC 132 is controlled by the CODEC control information from the central control unit 11.

  The 2-line / 4-line conversion unit 133 converts an analog line, which is a 2-line bidirectional communication path, into a 4-line signal composed of two lines in the transmission direction and two lines in the reception direction.

  The outgoing / incoming circuit 134 forms a loop with respect to the analog line at the time of outgoing call, and outputs a dial pulse as necessary, detects a ringing signal sent from the analog line at the time of incoming call, It is sent to the control unit 11. When an incoming call is answered, a loop is formed for the analog line. Further, polarity inversion detection is performed in a state where a loop is formed for the analog line.

  The polarity detection circuit 135 monitors the polarity state of the analog line and outputs polarity information. In the present invention, the polarity detection circuit 135 connects the terminal T12 to the L1 line of the analog line and the terminal T11 to the L2 line so that the polarity connection is opposite to the normal connection, and the L1 line is a battery (−48V). L2 line is ground (ground) analog line normal polarity (normal polarity information), or L1 line is ground (earth) and L2 line is battery (-48V) analog line reverse polarity The polarity information indicating whether the state (reverse polarity information) is present is sent to the central control unit 11.

  The principle of polarity detection in the polarity detection circuit 135 connected to the analog line in a normal state will be described with reference to FIG. 6A is a diagram in which the polarity detection circuit is connected to the analog lines L1 and L2 in a normal state, and FIG. 6B is a diagram in which the polarity detection circuit 135 is connected to the analog lines L1 and L2 in reverse polarity. FIG. The polarity detection circuit 135 is configured by connecting a bypass diode D, resistors R1 and R2, a photocoupler PC, and a power supply as shown in the figure, and uses a collector C of the diode of the photocoupler PC as an output terminal for polarity information. As shown in FIG. 6 (a), the polarity detection circuit 135 connected in the normal state is in the analog line normal polarity state (L1 line: -48V, L2 line: ground) (in standby mode), the current is Since the light-receiving side transistor of the photocoupler (PC) is turned off because it flows through the bypass diode (D) side, + 5V polarity information (normal polarity information) is output, and the analog line inversion polarity state (L1 line: ground, L2 line) : -48V) (when receiving), since the current flows through the light emitting diode of the PC, the light receiving transistor of the PC is turned on and outputs ground polarity information (inverted polarity information).

  In the present invention, as shown in FIG. 6B, the polarity detection circuit 135 having the above-described configuration provided in the external line circuit unit 13 has an analog line L1 line as an analog line terminal T12 and an analog line L2 line as an analog line. It connects to an analog line so that it may become a reverse polarity connection connected to terminal T11. In other words, in the present invention, the connection polarity during standby is reversely connected from the beginning. In the present invention, the polarity detection circuit 135 outputs the ground polarity information (inverted polarity information) when the analog line inversion polarity (standby) is turned on, and outputs the ground polarity information (inverted polarity information). ), The PC light-receiving transistor turns off and outputs + 5V polarity information (normal polarity information). If the analog line is disconnected, the potential disappears, the PC light-emitting diode does not emit light, and the light-receiving transistor turns on. The polarity information of + 5V which is the same as the incoming call is output in the off state. The polarity detection circuit 135 connected in reverse polarity to the analog line outputs normal polarity information which is the same polarity information of +5 V when the analog line is normal polarity and when the analog line is disconnected, so the analog line is disconnected with respect to the normal polarity information. By having a means for determining that it is, a disconnection detection function is realized. That is, it is determined that the analog line is disconnected when the calling signal is not detected on the analog line for a predetermined time after the normal polarity information exists.

  Next, an outline of a functional configuration in the central control unit 11 in the key telephone main apparatus 10 to which the analog line according to the present invention is connected in reverse polarity will be described with reference to FIG. FIG. 3 shows only the parts related to the present invention. In FIG. 3, the central control unit 11 of the key telephone main device 10 includes an analog line state control unit 111, an outgoing / incoming collision prevention unit 112, a data transmission / reception unit 113, a disconnection detection unit 114, a disconnection notification unit 115, Incoming call detecting means 116 and incoming call processing means 117 are provided.

  The analog line state control means 111 is activated at a constant cycle (for example, 100 mSec), monitors the polarity information sent from the polarity detection circuit 135 of the external line circuit unit 13, and detects the polarity state of the analog line. This is a means for shifting the state of the external circuit section 13 according to the change in the polarity state and performing various processes. The analog line state control means 111 has an incoming call detection timer and a polarity monitoring timer. The analog line state control unit 111 monitors whether or not the polarity information from the external line circuit unit 13 is changed while the state of the analog line (outside line) is in a standby state (waiting for an outside line). The external line state is shifted to the external line incoming detection state (external wear detection) and the incoming call detection timer is set (since the calling signal is generally sent at a cycle of 1 second on / 2 seconds off, For example, 4 seconds is used for the incoming call detection timer). Next, the analog line state control unit 111 monitors the polarity information from the polarity detection circuit 135 of the external line circuit unit 13 while the external line state is detected as an external line, and determines that the incoming call is abandoned if there is a change in the polarity information. Then, the state of the outside line is shifted to the outside line waiting state. If there is no change in polarity information during the detection of outer wear, the analog line state control means 111 determines whether the incoming call detection timer has timed out by minus 1, and can detect a call signal (incoming information) if timed out. It is determined that there has not been, and the state of the outside line is shifted to the polarity monitoring state (during polarity monitoring), and the polarity monitoring timer is set (for example, 4 seconds is used). Next, the analog line state control unit 111 monitors the polarity information from the polarity detection circuit 135 of the external line circuit unit 13 while the external line state is monitoring the polarity, and determines that the incoming call is abandoned if there is a change in the polarity information. The state of the outside line is shifted to the outside line waiting state. When there is no change in the polarity information, the analog line state control means 111 determines whether or not the polarity monitoring timer has timed out by minus 1, and if it has timed out, the connection polarity of the external line circuit unit 13 having the polarity detection circuit 135 Is determined to be a reverse polarity connection, the state of the outside line is shifted to the outside line standby state, and so-called nonpolar connection is dealt with.

  When the analog line state detection control stage 111 detects a change in polarity information, the outgoing / incoming collision prevention unit 112 shifts the state of the outside line from the standby state (waiting for the outside line) to the state where the outside line incoming call is being detected (detecting the outside line). When the outside line is in a state other than waiting for outside line, the transmission using the outside line circuit unit is restricted (prohibited).

  The data transmission / reception means 113 normally transmits the data to be transmitted to the key telephone 20 requested by other control means to the key telephone 20 via the extension circuit unit 15, and is also transmitted from the key telephone 20 to the extension. The data received by the circuit unit 15 is transferred to other control means. When the disconnection display information is received from the disconnection detection means 114, the disconnection display information is transmitted to the key telephone 20 via the data transmission / reception circuit 113.

  The disconnection detecting means 114 shifts the outside line state to polarity monitoring when the analog line state control means 111 cannot detect the incoming call for a certain period of time (for example, setting the incoming call detection timer = 4 seconds) while detecting the outer wear. When there is no incoming call detection and there is no change in polarity information during polarity monitoring for a certain time (for example, polarity monitoring timer = 4 seconds) When it is a change from information to normal polarity information, it is determined that the analog line is disconnected. When the disconnection is detected, a disconnection information display instruction is given to the disconnection display 30 of the key telephone 20 via the data transmission / reception means 113, and the disconnection information 17 is displayed on the disconnection display 17 of the key telephone main device 10.

  The disconnection notification unit 115 communicates with an external device via the disconnection notification unit 18 and, when the disconnection detection unit 114 detects a disconnection, notifies the external device of the disconnection information via the disconnection notification unit 18. An external device (for example, a personal computer) notified of the disconnection information can notify a monitoring system or the like via a wireless line (for example, a PHS communication card) that an abnormality has occurred (an analog line is disconnected).

  The incoming call detection means 116 monitors the incoming information from the external line circuit unit 13 while the external line status is detecting the outer wear and monitoring the polarity. When the incoming call information is detected, the incoming line detection means 116 shifts the external line status to the incoming call. Take over to the processing means 117.

  The incoming call processing means 117 issues an incoming call sound transmission instruction and an incoming call display instruction to the key telephone 20 when the outside line state is in the incoming state, and puts the key telephone 20 into the incoming state.

  Next, an outline of processing in each means relating to the present invention will be described using the flowchart of FIG. FIG. 4 mainly shows portions related to the present invention.

  The key telephone main device 10 sequentially performs an external line state monitoring process on one or more external lines 13-1 to 13-n at a constant cycle (for example, 100 mSec), and when one line process is completed as shown in FIG. However, in the following explanation, the description of the transition to “next outside line processing” will be omitted, and only the processing for one line outside line will be described.

  First, the state of the outside line is determined at the beginning of the process. That is, it is determined whether it is waiting for an outside line (S101), whether it is detecting an incoming line (S201), or whether it is monitoring a polarity (S301), and proceeds to the next process according to each state. Other processing (S401) is performed.

  In the case of waiting for the outside line state in the outside line state monitoring process (S101), the presence or absence of change in polarity information, which is the result of monitoring the polarity of the analog line, is monitored (S102), and there is a change in polarity information (normal polarity information) , Reverse polarity information, or reverse polarity information to normal polarity information), the state of the external line is shifted to the external line incoming detection state (external wear detection) (S103), and the incoming detection timer is set (S104). Although not shown, the storage unit 16 stores whether the change in the polarity of the analog line is the change from the normal polarity information to the reverse polarity information or the change from the reverse polarity information to the normal polarity information.

  Next, it is determined whether or not outer wear is being detected (S201). If outer wear is being detected, incoming information is monitored to determine whether incoming information has been detected (S202). When incoming information is detected, the state of the outside line is shifted to outside line incoming (S203), and outside line incoming processing is performed (S204). In step S202, if the incoming information cannot be detected, the polarity information is monitored (S205). If there is a change in the polarity information, it is determined that the incoming call has been abandoned, and the state of the outside line is shifted to waiting for the outside line (S211). In the polarity information monitoring process (S205), when there is no change in the polarity information, the incoming detection timer is set to minus 1 (S206) to determine whether it has timed out (S207). Is detected, and the state of the outside line is shifted to the polarity monitoring state (polarity monitoring is in progress) (S208), and the polarity monitoring timer is set (S209). Next, in order to notify the user that the outside line cannot be used, an outside line lamp lighting process is performed (S210).

  Next, in a state where no outside line is waiting and no outerwear is detected, it is determined whether or not polarity monitoring is in progress (S301). If polarity monitoring is in progress, incoming information is monitored (S302), and incoming information is detected. Shifts the state of the outside line to an incoming line (S303), and performs an incoming line process (S304). In the incoming information monitoring process (S302), when incoming information cannot be detected, the polarity information is monitored to check whether there is a change in polarity information (S305). The outside line state is shifted to the outside line standby state (S311), and the outside line lamp is turned off (S312). In the polarity change monitoring process (S305), when there is no change in the polarity information, the polarity monitoring timer is set to minus 1 (S306) to determine whether it has timed out (S307). Detection processing (S308, S309, S313) and disconnection notification processing (S310) in the disconnection notification means 115 are performed. Thereafter, the state of the outside line is shifted to the outside line standby state (S311), and the outside line lamp extinguishing process (S312) is performed to cope with so-called nonpolar connection.

  The disconnection detection process in the disconnection detection means 114 determines whether the polarity change of the analog line when the transition is made during the detection of the outer wear was a change from the reverse polarity information to the normal polarity information (S308). It is determined that the line is disconnected. When the disconnection is detected, a disconnection information display instruction is issued to the disconnection display 30 of the key telephone 20 via the data transmission / reception means 113, and control is performed to display the disconnection information on the disconnection display 17 of the key telephone main device 10 ( S309). In the case of No in step S308, it is determined that the disconnection has been recovered, a disconnection information display stop instruction is issued to the disconnection indicator 30 of the key telephone 20 via the data transmission / reception means 113, and the disconnection display of the key telephone main unit 10 is displayed. Control to stop the disconnection information display on the device 17 is performed (S313).

  As described above, the present invention is a key telephone main apparatus having a function of having one or more analog lines and a plurality of extensions and capable of connecting the analog lines with no polarity, and a plurality of button telephones connected to the extensions. A polarity detection circuit that detects whether the connection polarity of the analog line during standby is normal polarity or reverse polarity, and reverses the connection polarity during standby of the analog line from the beginning. When the polarity detection circuit detects that the polarity detection circuit changes from the reverse polarity to the normal polarity, the disconnection detection means determines that the analog line is disconnected, and the disconnection detection means detects the disconnection of the analog line. Then, by providing a disconnection notification means for notifying the disconnection detection information to the outside, for example, when configuring a monitoring system using this button telephone device, an analog When the line is disconnected, the mobile phones detection information cleavage and sensors analog line is detected via the external device, it is possible to notify the central monitoring unit.

Schematic configuration of the key telephone main device 10 according to the present invention. Schematic configuration of the key telephone 20 according to the present invention Functional block diagram of the central control unit 11 of the key telephone main device according to the present invention. The flowchart explaining the outline of the process of each means in the central control part 11 of the key telephone main apparatus 10 concerning this invention. Detailed configuration diagram of the outside line circuit unit 13 of the key telephone main device 10 Schematic circuit diagram of the polarity detection circuit 43 of the external line circuit unit 13 of the key telephone main device 10

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Key telephone main unit, 11 ... Central control part, 12 ... Call path switch part, 13 ... Outer circuit part, 14 ... Voice guidance transmission part, 15 ... Extension circuit part, 16 ... Memory | storage part, 17 ... Disconnection indicator, DESCRIPTION OF SYMBOLS 18 ... Disconnection notification part, 20 ... Key telephone, 21 ... Control part, 22 ... Data transmission / reception circuit, 23 ... Voice processing part, 24 ... Handset, 25 ... Speaker, 26 ... Dial key, 27 ... Outside line key, 28 ... Function Key, 29 ... LCD display, 30 ... Disconnection display, 111 ... Analog line state control means, 112 ... Outgoing / receiving collision prevention means, 113 ... Data transmission / reception means, 114 ... Disconnection detection means, 115 ... Disconnection notification means, 116 ... Incoming call detection means, 117 ... incoming call processing means, 131 ... highway interface circuit (I / F), 132 ... codec circuit (CODEC), 133 ... 2-wire / 4-wire conversion, 34 ... outgoing / incoming circuit, 135 ... polarity detection circuit.

Claims (6)

In a key telephone apparatus comprising a key telephone main unit having a function of accommodating one or more analog lines and a plurality of extensions and connecting the analog lines in a non-polar manner, and a plurality of button telephones connected to the extensions,
The key telephone main device includes incoming call detection means for detecting incoming information from the analog line;
A polarity detection circuit that detects the polarity of the analog line, detects normal polarity and outputs normal polarity information, detects reverse polarity and outputs reverse polarity information;
The polar detection circuit when connected in reverse polarity connection polarity during standby of the analog line from an initial, by detecting the polarity information said polarity detection circuit is output is changed to the normal polarity information from the inverted polarity information Disconnection detecting means for determining that the analog line is disconnected if the incoming call detecting means does not detect incoming information within a predetermined time from ,
A button telephone apparatus comprising: a disconnection notification means for notifying the outside of disconnection detection information when the disconnection detection means determines that the analog line is disconnected. The button telephone apparatus according to claim 1, wherein
The key telephone apparatus is provided with a function of displaying disconnection detection information when the disconnection detecting means of the key telephone main apparatus determines that the analog line is disconnected . The button telephone apparatus according to claim 1 or 2,
The key telephone main device is provided with a function of displaying disconnection detection information when the disconnection detecting means determines that the analog line is disconnected. In the key telephone main device constituting the key telephone device comprising the key telephone main device and a plurality of key telephones connected to the extension of the key telephone main device,
  A function capable of accommodating one or more analog lines and a plurality of extensions and connecting the analog lines without polarity;
  Incoming call detection means for detecting incoming information from the analog line;
  A polarity detection circuit that detects the polarity of the analog line, detects normal polarity and outputs normal polarity information, detects reverse polarity and outputs reverse polarity information;
  When the polarity detection circuit is connected in the reverse polarity from the initial connection polarity of the analog line, it detects that the polarity information output from the polarity detection circuit has changed from reverse polarity information to normal polarity information. Disconnection detecting means for determining that the analog line is disconnected if the incoming call detecting means does not detect incoming information within a predetermined time from,
  A key telephone main apparatus comprising: a disconnection notification means for notifying the outside of disconnection detection information when the disconnection detection means determines that the analog line is disconnected. The key telephone main device according to claim 4,
A key telephone main apparatus comprising a function of notifying the key telephone of disconnection detection information when the disconnection detecting means determines that the analog line is disconnected . In the key telephone main device according to claim 4 or 5,
A key telephone main apparatus comprising a function of displaying disconnection detection information when the disconnection detecting means determines that the analog line is disconnected .

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