JP3761459B2 - Station equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a two-wire digital subscriber line intra-station terminating device (hereinafter referred to as an intra-station device) using a ping-pong transmission system, and more particularly to improvement of power consumption.
[0002]
[Prior art]
Conventionally, this type of in-station device is installed on the side of the station building and connected to the in-house device at the subscriber's home via a subscriber line. This in-station device has functions for terminating the subscriber line, supplying power to the in-home device, monitoring the DC loop current, and the like.
[0003]
Further, in this type of in-station device, generally, the power consumption of -48V is reduced when there is no call by adopting a call-by-call power supply method that reverses the power supply polarity according to the call state. With the increase of ISDN services in recent years, the number of in-station devices has increased, and further improvements in power costs, such as measures to reduce power consumption in individual circuits within the devices, are required. Technologies have been proposed.
[0004]
For example, in Japanese Patent Laid-Open No. 10-313298, the ping-pong transmission apparatus consumes by temporarily storing all received data for one reception period in a buffer memory and reducing the DSP clock frequency for signal reception to ½. Reducing power is disclosed.
[0005]
Further, in Japanese Patent Laid-Open No. 11-145939, the power consumption of the line termination unit is reduced to ½ by supplying power only during the reception period within one burst period using the characteristics of the ping-pong transmission apparatus. It is disclosed.
[0006]
Japanese Patent Laid-Open No. 11-55698 discloses reducing power consumption in a subscriber line termination device by stopping clock supply to the CPU circuit of the subscriber line interface when the DC loop current is off. Has been.
[0007]
[Problems to be solved by the invention]
The above-described conventional in-station device has the following problems. The inventions disclosed in Japanese Patent Application Laid-Open Nos. 10-313298 and 11-145939 use the transmission / reception burst period of ping-pong transmission to place part of the transmission / reception circuit in the sleep state, thereby reducing the power consumption of the entire in-station device. In view of the entire transmission / reception circuit, only a part of the power consumption can be reduced. Furthermore, from the viewpoint of power consumption of the entire station, there is a problem that power consumption is not sufficiently reduced.
[0008]
For example, in the invention of Japanese Patent Laid-Open No. 10-313298, the clock frequency of the DSP for signal reception is ½, but the circuit operation itself continues to operate and is not in a completely stopped state. No measures are taken for power reduction during standby. Also, in the invention of Japanese Patent Laid-Open No. 11-145939, the power supply to the line termination circuit is stopped at the time of burst communication.
[0009]
Further, the invention of Japanese Patent Laid-Open No. 11-55698 only stops the clock supply to the CPU circuit of the subscriber line interface, and the peripheral circuits of the oscillator and the termination circuit installed outside are still in the operating state. Nothing has been done about the power consumption of the 48V system.
[0010]
ISDN employs a call-by-call power supply system, and uses a system that performs communication by reversing the power supply polarity during standby and power supply during outgoing / incoming calls. The 48V DC power supply could not be stopped, and the above-described prior art was limited to the effect of only + 5V, or the line was only considered when idle.
[0011]
The present invention has been made in view of the above problems, and the present invention is an intra-station apparatus adopting a two-wire digital subscriber line transmission system, not only during a call but also during a non-call (standby). It is an object of the present invention to provide an in-station device capable of greatly reducing power consumption with an inexpensive and simple configuration.
[0012]
[Means for Solving the Problems]
The invention according to claim 1 is an in-station device that is connected to a home device via a subscriber line and has a DC power source that supplies power to the home device via the subscriber line. A DC current is supplied to the in-home device, and when the DC loop current of the subscriber line exceeds a certain value, a DC power source that sends a DC power source detection signal is detected, and when the DC power source detection signal is detected, a power-down control of the in-device circuit is performed. DC power to turn off the DC power supply when the power-down control means to be performed and the DC power supply detection signal is sent, and the DC power supply is turned off according to the control of the power-down control means and the activation of the in-home device is detected. Power supply control means, the DC power supply control means to the subscriber line according to the control of the power down control means while the DC power supply detection signal is sent Flowing a weak current, the off the DC power supply and a weak current flows, the said optical network unit is activated weak current, characterized in that on the DC power supply in the stopped.
[0015]
According to a second aspect of the present invention, the DC power supply control means includes a weak power supply, a switching means for turning on / off the connection to the subscriber line under the control of the power-down control means, and the subscriber line and the premises from the weak power supply. Weak current detection means for detecting the conduction of the weak current flowing through the device, and the weak current detection means turns off the DC power supply when detecting the conduction of the weak current, and detects the stop of the weak current The DC power supply is sometimes turned on.
[0016]
The invention described in claim 3 is characterized in that the weak current detecting means is constituted by a photocoupler.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing the configuration of this embodiment. The in-station device 1 is connected to the in-home device 2 through the subscriber line 3, and a line terminal unit (CT unit) 4 that performs control according to various line conditions, and the in-home device 2 through the subscriber line 3. A DC power source 5 for supplying a DC current to the subscriber line 3 and sending a DC current detection signal when the DC loop current of the subscriber line 3 exceeds a certain value; a transmission line terminating unit (LT unit) 11 for receiving the line; A pulse transformer 19 for transmitting / receiving a subscriber pulse, a capacitor 18 for cutting a DC current superimposed on the subscriber line 3, and a CT section 4 used for detecting a clock interruption, converting a speed of ping-pong transmission, and the like. Oscillator (XT unit) 14, SW 3 unit 17 for turning on / off XT unit 14, switch 20 for turning on / off connection of subscriber line 3 and DC power supply 5, and a weak current flow through subscriber line 3, and their conduction Home interior with or without By detecting the second state comprises a DC power supply control unit 21 for turning on and off the DC power source 5.
[0018]
The DC power supply control unit 21 controls the power down control circuit 9 to turn on / off the connection with the subscriber line 3, and when the SW 4 unit 211 is on, a weak current flows to the subscriber line 3. It has a power supply 212, a photocoupler 213 that is turned on when a weak current is conducted, and resistors 214 and 215 that are current limiting resistors of the photocoupler 213.
[0019]
When the SW4 unit 211 is turned on by the control of the power down control circuit 9, the DC power supply control unit 21 causes a weak current to flow from the power supply 212 to the photocoupler 213 through the subscriber line 3 and the home device 2. When the photocoupler 213 is turned on due to the conduction of the weak current, the DC power supply control unit 21 sends ground signals S1 and S2 from the open collector terminals 216 and 217 of the photocoupler 213.
[0020]
In addition, the CT unit 4 performs upstream FHW and downstream BHW data communication, and processes a control signal and a status signal, and by detecting a direct current detection signal sent from the direct current power source 5, A DC loop current (DL) detection circuit 8 that detects a DC loop current of the subscriber line 3 and a power-down control circuit that sends out a power control signal of the in-device circuit in accordance with a DC loop current detection notification from the DL detection circuit 8 9, a ping-pong transmission speed conversion memory 7 for performing speed conversion for performing ping-pong transmission (burst communication), a clock break detection unit 13 for performing break detection of 320 / 0.4k clock, and an LT unit 11 LT power control unit 10 that performs power control in this manner, and PLL 1 that supplies a clock to LT power control unit 10 and ping-pong transmission rate conversion memory 7 When, with a power-down control SW1 parts 15 to on-off operation by the circuit 9, SW2 parts 16, SW3 parts 17.
[0021]
The in-home device 2 shown in the figure is well known to those skilled in the art and is not directly related to the present invention, and thus detailed description thereof is omitted.
[0022]
Next, the operation of the present embodiment will be described in detail with reference to the drawings. FIG. 2 is a block diagram showing the operation of this embodiment. The CT unit 4 receives the BHW data by the CO / ST unit 6 and executes various line processes according to the control signal. The main signal data is converted into a burst signal having a period of 0.4 kHz by the ping-pong transmission rate conversion memory 7, and the transmission data is transmitted as AC data to the subscriber line 3 via the pulse transformer 19 and the switch 20.
[0023]
The received data is corrected from the in-home device 2 via the pulse transformer 19, corrected by the LT unit 11 such as gain adjustment, and after speed conversion, a status signal is added and output to the FHW. The DC power source 5 sends a DC loop current (DL) detection signal to the CT unit 4 when the DC loop current of the subscriber line 3 exceeds a certain value. The DL detection circuit 8 notifies the power-down control circuit 9 of DL detection after a certain protection time, and the power-down control circuit 9 that has received the notification notifies each SW1 unit 15, SW2 unit 16, and SW3 unit 17 to each line. Perform on / off control suitable for the condition.
[0024]
First, a state where communication is not performed (standby state) will be described. First, the subscriber line 3 is switched from the communication state (reverse power supply) to the normal end of power supply (layer 1 standby state). When the current value of the subscriber line 3 becomes equal to or lower than the detection threshold, the DC power source 5 changes the DL signal to the OFF state and stops sending the DC loop current detection signal. When the transmission of this signal is stopped, the DL detection circuit 8 notifies the power-down control circuit 9 that the DC loop current detection signal is turned off after a certain protection time has elapsed. As a result, the power down control circuit 9 determines that the layer 1 is stopped, and turns on the switches of the SW 1 unit 15, SW 2 unit 16, and SW 3 unit 17 all at once to perform “power down” control.
[0025]
Here, the SW 1 unit 15 is an operation stop SW of the LT unit 11. In the standby state, the receiving unit does not need to operate, so the operation is stopped. The SW2 unit 16 is for stopping the 320 / 0.4k clock supply to the ping-pong transmission rate conversion memory 7. Similar to the LT unit 11, the ping-pong transmission rate conversion memory 7 is a circuit that does not require operation during standby. The SW3 unit 17 is for powering off the XT unit 14 (15.36 MHz oscillator).
[0026]
When the SW3 unit 17 is operated, the clock supply to the PLL 12 and the clock loss detection unit 13 is stopped. Subsequently, all the clocks from the PLL 12 are also stopped, and the clock supply to the ping-pong transmission rate conversion memory 7 and the LT unit 11 is stopped. Conventionally, when the clock supply of the XT unit 14 is stopped, the clock disconnection detection unit 13 detects the clock disconnection, and the CO / ST processing unit 6 loses CO / ST (all “0”). For this reason, the CT unit determines transmission / reception based on the presence / absence of a DC loop current detection signal, and for standby, the clock loss detection is masked by the processing of the CO / ST processing unit 6. Since FHW and BHW are operated by MCK and SCK, they can operate without being affected by the control operation of CO / ST, and there is no problem even if the clock of XT section 14 is stopped.
[0027]
When the SW1 unit 15, SW2 unit 16, and SW3 unit 17 are in a power-down state, the switch 20 is subsequently turned off and the SW4 unit 211 is turned on at the same time. Then, a loop circuit is formed via the subscriber line 3 and the in-home device 2, and the power source 212 supplies a current corresponding to the line resistance and the current limiting resistance 214. As an example, when a + 5V power supply is used as the power supply 212, the subscriber line resistance is about 4 to 5 k ohms when considered as the minimum value and the maximum value (810 ohms).
[0028]
When a current flows, the photocoupler 213 is turned on, and the open collector terminals 216 and 217 connected to the pull-up resistor 215 send ground signals S1 and S2. The ground signal S <b> 1 performs sleep control for the DC power supply 5. Upon receiving the ground signal S1, the DC power supply 5 cuts the primary side circuit and stops oscillation. As a result, the DC power supply 5 completely shifts to the sleep mode. When the ground signal S2 is input to the power-down control circuit 9, the power-down control circuit 9 identifies that the line is completely in a standby state.
[0029]
Next, operation during communication will be described. First, at the time of calling, the subscriber line polarity is reversed by the activation of the in-home device 2, and the current flowing through the diode of the photocoupler 213 is stopped. Then, the ground signals S1 and S2 sent from the open collector terminals 216 and 217, which are outputs of the photocoupler 213, are changed to high level outputs.
[0030]
As a result, the DC power supply 5 returns from sleep, and the power-down control circuit 9 turns off the SW4 unit 211 and separates the DC power supply control unit 21 from the subscriber line 3. Then, the switch 20 is turned on, and the DC power supply 5 starts to supply current. As a result, the DC power supply 5 sends a detection signal to the DL detection circuit 8 when it detects a current of a certain value or more, and the power-down control circuit 9 shifts to the startup state.
[0031]
At the time of an incoming call, if there is an incoming call request from the BHW, control stop information is sent from the CO / ST processing unit 6 to the power-down control circuit 9. The power-down control circuit 9 turns off the SW4 unit 211 and turns on the switch 20. When the DC loop DC starts to flow through the subscriber line 3, the DL detection circuit 8 detects the DC loop current based on the DC loop current detection signal from the DC power supply 5, and transmits a power down release signal to the power down control circuit 9. To do. At this time, the power-down control circuit 9 immediately stops the control of the SW1 unit 15, SW2 unit 16, and SW3 unit 17, so that the circuits and the oscillator are turned on and start to operate again. Thereafter, a normal layer 1 activation operation is performed, and communication is started without any problem.
[0032]
Note that the SW1 unit 15 is turned off, but when the DC loop current is flowing and the CO / ST processing unit 6 is operating, the LT power control 10 independently controls the power of the SW1 unit 15 and receives the signal. Is turned on and turned off during transmission. As a result, even during transmission / reception, it is possible to operate with 1/2 of the conventional power consumption.
[0033]
Next, the operation of the DC power supply control unit 21 when the in-home device 2 is in the standby state will be described in detail with reference to FIG. The power supply 212 can be realized by using an appropriate power supply in the apparatus, but here, +5 V is used as an example.
[0034]
When the home device 2 is in the standby state, the SW4 unit 211 is turned on, and a loop circuit is configured by the internal diode D1, the current limiting resistor 214 and the photocoupler 213 of the home device 2, and the current limiting resistor 214 and the subscriber line resistance are connected. A similar current flows. When the on-current of the photocoupler is about 1 mA, the resistance 214 is several k ohms, and even if the resistance value of the subscriber line 3 varies, the current value does not vary greatly.
[0035]
When the photocoupler 213 is turned on, the outputs of the open collector terminals 216 and 217 change from the potential of VCC to the ground. The ground signals S1 and S2 are input to the sleep terminal of the DC power source 5 and the power-down control circuit 9, and the oscillation of the DC power source 5 is stopped, and the power consumption of the -48V system is greatly reduced (measured by about 1 / 10).
[0036]
Next, the operation of the DC power supply control unit 21 when the in-home device 2 transitions from the standby state to the communication state will be described in detail with reference to FIG. When the home device 2 is activated, the diode D1 inside the home device is turned off and the photocoupler 213 is turned off. Then, the outputs of the open collector terminals 216 and 217 become the potential of VCC, the DC power supply 5 is released from sleep, and at the same time, the power-down control circuit 9 recognizes the activation of the in-home device 2. Subsequently, the diode D2 inside the in-home device 2 is turned on (actually a DC-DC converter is connected), the SW4 unit 211 is turned off, and the DC power supply control unit 21 is completely disconnected from the subscriber line 3, and the DC power supply 5 and a switch circuit via the switch 20 are configured, power supply to the in-home device 2 is started, and a transition is made to the communication state.
[0037]
Next, the operation timing of each switch and incoming / outgoing calls will be described in detail with reference to the time chart of FIG. First, the operation during standby (t ₀ -t ₁ interval in FIG. 5) will be described. At the time of standby, as shown in FIG. 4, a current flows to the diode D1 side inside the home device 2. At this time, since the switch 20 is off and no DC loop current flows through the subscriber line 3, the DC current detection circuit 8 is turned off. Since the SW 1 unit 15, SW 2 unit 16, and SW 3 unit 17 are in the power down mode, and the XT unit 14 stops oscillating when the SW 3 unit 17 is turned on, the CO / ST processing unit 6 performs mask processing. Masks unnecessary clock loss detection by turning it on.
[0038]
Further, the DC power supply control unit 21 turns on the photocoupler 213 when the SW4 unit 211 is turned on, and sends ground signals S1 and S2 from the open collector terminals 216 and 217.
[0039]
Next, the operation when transitioning to the communication state (t ₁ -t ₂ interval in FIG. 5) will be described. When the calling operation of the in-home device 2 occurs (t _{1 in} FIG. 5), the diode D1 is turned off and the diode D2 is turned on as shown in FIG. Then, the operation of the photocoupler 213 stops, and the outputs of the open collector terminals 216 and 217 are high. Along with this, the sleep of the DC power supply 5 is canceled, and at the same time, the activation of the in-home device 2 is notified to the power-down control circuit 9 by turning off the ground signal S2.
[0040]
When the in-home device 2 starts calling, the SW 4 unit 211 is turned off and the DC power source control unit 21 is released from the subscriber line 3 and at the same time the switch 20 is turned on, and power supply to the subscriber line 3 from the DC power source 5 is started. Is done. Then, the DL detection circuit 8 is turned on, the SW2 unit 16 and the SW3 unit 17 turn off the power-off control, and normal communication is started. Further, the mask processing of the CO / ST processing unit 6 is also turned off with the resumption of the clock supply from the XT unit 14.
[0041]
Thereafter, the SW1 unit 15 is turned off at the time of reception and turned on at the time of transmission, thereby intermittently starting the circuit operation of the LT unit 10 and reducing the power consumption by half. When the communication is terminated and the DC loop current detection detection circuit 8 turns off the transmission of the DC loop current detection signal due to the inversion of the subscriber line polarity, the power down control circuit 9 switches the SW1 part 15, SW2 part 16, SW3 part 17 , And the mask processing of the CO / ST processing unit 6 is shifted to the power down mode.
[0042]
When the DC loop current is completely turned off, the switch 20 is released (t _{2 in} FIG. 5), and when the SW4 unit 211 is turned on, when a current flows again to the photocoupler 213, the open collector terminals 216 and 217 The ground signal S1, S2 is sent out.
[0043]
At the time of an incoming call (t _{3 in} FIG. 5), when an incoming call activation command is received by a control signal from the BHW, the CO / ST processing unit 6 causes the power-down control circuit 9 to transition to a communication state. Then, the SW4 section 211 is turned off to stop the operation of the photocoupler 213. At the same time, when the switch 20 is turned on, the DC loop current starts flowing in the subscriber line 3 and when the DC loop current detection circuit 8 exceeds a certain value, the DC loop current detection circuit 8 Turn on. The subsequent operation is the same as that at the time of calling.
[0044]
Thus, according to the present embodiment, the power consumption can be reduced most efficiently without depending on the transmission / reception state and without affecting the operation line of the + 5V and −48V system circuits. It is obvious that the present invention is not limited to the above-described embodiment, and can be appropriately changed within the scope of the technical idea of the present invention.
[0045]
【The invention's effect】
As described above, according to the present invention, efficient power consumption reduction can be realized with an inexpensive and simple configuration.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a configuration of an embodiment.
FIG. 2 is a block diagram showing the operation of the present embodiment.
FIG. 3 is a block diagram showing the operation of the DC power supply control unit 21 when the home device 2 is in a standby state.
FIG. 4 is a block diagram showing the operation of the DC power supply control unit 21 when the home device 2 is in a communication state.
FIG. 5 is a time chart showing the operation of the present embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 In-station apparatus 2 In-home apparatus 3 Subscriber line 4 Line termination (CT) part 5 DC power supply 6 CO / ST processing part 7 Ping-pong transmission rate conversion memory 8 DC loop current (DL) detection circuit 9 Power-down control circuit 10 Transmission line termination (LT) unit power control unit 11 transmission line termination (LT) unit 12 PLL
13 Clock loss detection unit 14 Oscillator (XT unit)
15-17 SW1-3
18 Capacitor 19 Pulse transformer 20 Switch 21 DC power supply controller 211 SW4
212 Power supply 213 Photocoupler 214, 215 Resistance 216, 217 Open collector terminal

Claims (3)

In the in-station device having a DC power source connected to the in-home device via the subscriber line and supplying power to the in-home device via the subscriber line,
A DC power supply for supplying a DC current to the in-home device via the subscriber line, and sending a DC power supply detection signal when a DC loop current of the subscriber line exceeds a certain value;
Power down control means for performing power down control of the circuit in the apparatus upon detecting the DC power supply detection signal;
While the DC power supply detection signal is being sent, the DC power supply is turned off according to the control of the power-down control means, and the DC power supply control means for turning on the DC power supply when the activation of the home device is detected,
The DC power supply control means causes a weak current to flow through the subscriber line according to the control of the power-down control means while the DC power supply detection signal is being sent, and turns off the DC power supply when the weak current flows. The in-station device is characterized in that when the in-home device is activated, the weak current is stopped and the DC power supply is turned on.   The DC power supply control means includes a weak power supply, a switching means for turning on / off the connection with the subscriber line under the control of the power-down control means, and a weak current flowing from the weak power supply through the subscriber line and the in-home device. A weak current detecting means for detecting the continuity of the weak current, the weak current detecting means turning off the DC power supply when detecting the continuity of the weak current, and turning on the DC power supply when detecting the stop of the weak current. The in-station device according to claim 1, wherein   3. The intra-station apparatus according to claim 2, wherein the weak current detection means is constituted by a photocoupler.

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