JPS5873292A - Check mechanism for terminal device in catv system - Google Patents

Abstract

PURPOSE:To check the function of a terminal without deassembling it, by providing an optical communication means for the terminal device and a check device. CONSTITUTION:A terminal device 28 consists of a main box 10, a TV receiver 11, and a control box 12. A check signal from a check device 40 is transmitted to a light emitting element 38 via an optical communication section 39 and a data signal is converted into rays and inputted to a photodetector 35 and to a data processing section 32 via an optical communication section 33 to transmit the data signal of response corresponding to the data signal for check to the optical communication section 33. This signal is converted into rays with a light emitting element 34, transmitted to a photodetector 37 and given to the check device 40 via the optical communication section 39.

Description

[Detailed description of the invention]

The present invention relates to a CATV system that can send many video signals from one center to many terminal devices and perform two-way data communication between the center and the terminal devices, and in particular, the present invention relates to a CATV system that is capable of transmitting many video signals from one center to many terminal devices and performing two-way data communication between the center and the terminal devices. CATv that can directly test
Relates to the inspection mechanism for terminal devices included in the system. In recent years, with the development of electronic equipment, 0ATV systems that transmit and receive video signals and data signals using cables have been put into practical use. This CΔT-V system has an independent signal transmission path using a cable, and its usable frequency band is extremely wide.
−． It is possible to transmit 80 channels at the same time, and its usage range is not limited to the viewing area.
b-noguar is about to develop into a new and powerful communication medium. In addition, by taking advantage of the characteristics of this wide band, we can allocate a portion of it to data transmission by digital devices.
In addition, 11 digital channels were installed in the opposite direction, and mutual communication services were put into practical use. First, an outline of the conventional 0ATV system will be explained with reference to FIG. Figure 1 shows the entire CATV system. This system consists of one center 1 and a terminal device 28 installed in each household 2.
The center 1 and the terminal HM2g of each house l112 are connected by a coaxial cable. Main line Couple 3 from Center 1
is drawn out, and a trunk amplifier 4 and a branch 5 are provided at predetermined locations on the trunk cable 3. A plurality of branch cables 6 are drawn out from this branch 5, and each branch cable 6 is provided with an extension amplifier 1 and a tap-off 8 at a predetermined location. From each tap-off 8 there are multiple branch lines,
9. are pulled out, and the ends of each branch cable 9 are led into each home 2. Terminal equipment in each household 2 @
28 consists of a main box 10, a television receiver 11, and a control box 12, and the end of the branch cable 9 is connected to the main box ION, and the television receiver 1
1 and 12 are connected to the main box 10, respectively. In other words, center 1 and each house are like a Christmas tree! i1
The two terminal devices 28 are subdivided and connected. A seven receiving/receiving terminal J-13 is set up outside the center 1, and the receiving terminal 113 is connected to one immosulator 15 in the source group 14. This source group 14 includes a video disk player 16 and a video tape recorder 17.
, Studio No. 18, etc. Receives signals from this source group 14.

[The modulation sending unit 19 consists of two types of systems,
There is a system of an F mosulation circuit 2o, a scramble circuit 21, and an up-inverter circuit 22, and a system of an IF modulation circuit 23 and an up-inverter circuit 24, and the outputs of the amplifier inverter circuits 22 and 24 are connected to the main cable 3, respectively. It is. Further, a data transmitter/receiver 25 for communicating with each main box 1o is connected to the trunk couple 3, a simulator 26 is connected to the data transmitter/receiver 25, and a computer 26 has a printer, a display, etc. Peripheral equipment @2
7 is connected. Next, the operation of the present ATV system will be explained. Turn on the television receiver 11 and select the desired channel by operating the -] button 1 to roll box 12.The frequency of the channel you are trying to receive is converted to an empty channel that is not on air and the image is received using the Remain box 10. Supply to 41111. control box 12
The types of channels that can be selected can be divided into the following groups: (A) retransmission that receives TV radio waves as they are, (B) independent programs (free), and (C) public F1 programs. Each group has several channels, and a total of about 30 to 80 selections are possible. (Δ) Retransmission The TV radio waves received by the reception antenna 13 are −N demodulated by the i-imosulator 15 and output to the modulation transmitter 19 . Preferably, I'modulate circuit 23 (modulated,
The modulated No. 15 is increased to a specific frequency by an up-inverter 24. This signal number is modulated, assigned a position number to a specific channel, and is transmitted to each house E12 via the main line Kunoru 3, branch cable 6, and branch cable 9, and is received by the TV receiver 111 of the terminal device 28. . (B) There are independent programs such as weather forecasts, youth programs, etc. Recorded programs by ISQPLAY-A116, Video Chief Player 1-DA17, and live programs produced at Studio 18 are I'
The signal is modulated by a modulation circuit 23 and an up-inverter circuit 24, frequency-converted to a specific frequency, and transmitted to the trunk cable 3. This program has been received 41 times, v1! l Nigawara f free of charge,
Each home can receive iI2 images for a basic monthly fee. (C) Paid programs New movies and specific programs, such as recorded programs by the video disc play 1116 and video cheap play 11, and live programs produced by the studio 18 (-) are modulated by the IF modulation circuit 20. At the same time, a scramble circuit 21 adds a specific synchronizing signal to the image signal so that it does not become a perfect image even if it is received as is.Next, an inverter circuit 22 converts the frequency of a specific channel to That frequency is sent to the trunk cable 3.When each household 2'c'' wants to receive this pay program, the signal is sent within the member box 10.
The image signal can be demodulated into a normal image signal and transmitted to the RAD receiver 11, so that the image can be viewed on a normal screen. When this pay program is received, a preset fee is calculated and the monthly basic usage fee plus the special usage fee is charged. #&! However, the end of the terminal 1 household 2 and the unequipped unit 28 are connected by a coaxial cable, but which household 2
If you don't know which channel you're watching, you won't be able to tell the difference between paid and free programs, and it will send out search signals.
So-called polling is performed by calling the main box 10 of each terminal device 28 using an individual address number and checking whether the channel is being received at the time of the search. At this time, the main box 10 outputs a reply indicating which fv channel is being received at time A, and sends it to Data Transmission/Reception@925. This data transmission/reception
The received data of 125 is processed by the computer 1-2G, and is not displayed or printed by the peripheral device 27. This polling is carried out for a fixed period of time (every few seconds to one loss per second), so viewer ratings can be summed up quickly. By operating the control box 12, a person can respond to questions 1) in the program while watching the television receiver 11, and the response content (data) is sent to the center 1 via a coaxial cable. In such a CATV system, as shown in FIG.
Each terminal device 28 also houses a data transmitter/receiver (MO[)EM), a converter, a data processing unit, etc., and these configurations allow bidirectional data communication. It is something that can be done. Therefore, when checking whether the gamma digital communication system of a specific terminal device 28 is normal, the cable 9J polls the terminal device 2B, causes the terminal device 28 to send an uplink data signal, and - It was determined that the terminal device 28 was out of order when a problem occurred in the pattern of the F redata code. However, even if there is a defect in the upstream data signal pattern, it is possible to determine whether the defect in the upstream data signal originates from the data transmitter/receiver or from the data processing section. was inconvenient. Therefore, there is a need for an inspection device that can be directly connected to the terminal device 28 and inspect the terminal device 28 without going through a data transmitter/receiver. However, the terminal device 28 is modified to prevent eavesdropping from occurring.
When the outer shell cover is removed and the terminal device 28 is disassembled, a mechanism is built in that automatically stops the image receiving function and prevents the 7111 pair from being received again (Hatsuchio 12 mechanism). Therefore, disassembling the terminal device 28 and inspecting its functions would destroy the functions of the terminal device 12g (a), making the inspection impossible. In view of the above-mentioned drawbacks, the present invention provides a CATV system capable of testing functions by installing an optical communication means in a terminal device and installing an optical communication means in an inspection device, without disassembling the terminal device. This provides an inspection mechanism for terminal devices. An embodiment of the present invention will be described below with reference to the drawings. FIG. 2 is a block diagram showing the configuration inside the main box 1o behind the terminal '@ box 28. The branch line couple 9 is connected to a converter 30 and a data transmitter/receiver 31. and are interconnected with the data processing section 32. The television receiver 111 is connected to this converter 30, and the data processing section 3
2 is connected to the control box 12 described above. The data processing unit 32 includes an optical communication unit 33 that operates during inspection.
are connected to each other, and the optical communication section 33 has a light emitting diode or the like provided in the case of the main box 1o.
, the element 34 and a light receiving element 35 such as a phototransistor are connected. Reference numeral 36 denotes a measurement plug, which is used by plugging into the terminal device 28 during measurement, and is equipped with a light receiving element 37 such as a phototransistor and a light emitting element 38 such as a light emitting diode. Light emitting element 3
8 is connected to the optical communication section 39 in the flag 36, and is connected to the optical communication section 39 inspection device f 40 TOHA-J-F'
4NI J, -) Te phase rt<Z connection. FIG. 3 shows the external appearance of the inspection device 40. At the bottom right of the top surface of the panel, there is a key 42 for channel setting and for setting the terminal device to a specific state. An alpha 21-Merrick display 43 is provided on the upstream side to display chitunnel data. Further, a light emitting diode 45 for monitoring is provided on the left side of the upper surface of the inspection device 40. There is a connector 46 on the side of the inspection device 40.
is connected to this connector 46.
The plug 3 is connected to the tip of the lead 41.
6 is connected. The plug 36 has a cubic shape, and has 112 holes on its ridge.
The book insertion leg 47.48 protrudes! (Yes, these insertion legs 47 and 48 should be placed on one side so as not to insert the wrong place.
is to shorten its length. Figure 4 shows the aforementioned light emitting element 34.3g and light receiving element 35°3.
7, the insertion legs 47 and 48 are made of metal and have a hollow cylindrical shape;
．． 48 is a light beam), and a driver 49.50 is inserted through it. The lower end of this optical fiber cord 49.50 is located near the open end of the insertion leg 47.48, and the upper end of the optical fiber cord 49.50 is located between one part of the insertion leg 47.48 [a little protruding from the 1-1 end]. The light-receiving element f37 and the light-emitting element 38 are located close to the upper end of the bar 49.50 (this light) II (the light receiving element f37 and the light emitting element 38 are located close to the upper end of the bar 49.50, respectively. Also, on the back of the main box 10, there are spaces between the insertion legs 47.48). Inspection holes 51 at the same interval as
．． 52 is an opening, and a light emitting element 34 and a light receiving element 35 are provided at positions facing the inspection holes 51 and 52, respectively. It is fixed to 53. Next, the operation of this embodiment will be explained. The combination notebook 26 in the center 1 periodically polls all terminal devices 28 and sends commands to check whether their functions are normal. This test message is sent from the data transmitter/receiver 25 to all terminal devices @2B, and the terminal devices 28 with the corresponding address numbers return their operating status to the data transmitter/receiver 25 in the order in which they are called.
This response up? - data (I7 to computer 26)
analyzes and determines whether the terminal device 28 is in a normal state. Inspection via polling by the L-sitter 1 reveals whether the data transmission/reception @31 of the terminal device 28 is out of order or not. Since it is unknown whether the I32 is out of order or not, the address number of the terminal device 28 that has caused an inconvenience during the polling test is displayed, and the terminal device H28 that has been displayed is individually
is brought into each home 2 and the state and function of each terminal equipment 928 is inspected. In this inspection of the terminal device 28, as shown in FIG.
Insert. As a result, the light emitting element 34 and the light receiving element 31
The light-receiving cable 35 and the light-emitting element 38 face each other via the optical fiber cord 49 and the optical fiber cord 50, so that optical communication can be performed. In the test, the terminal unit w128 is set to a specific state by operating the keys 42, and instructions are given to select a specific mode using the numeric keypad. The selected t-code is displayed by an alpha nymeric display 43 and a light emitting diode 45. The inspection signal from the inspection device 40 is transmitted to the light emitting element 38 via the optical communication section 39, converted into a beam of light, and transmitted to the light receiving element 35 via the optical fiber code 48. The data signal input to the light receiving element 35 is sent to the data processing section 32 via the optical communication section 33, and the response data No. 5 corresponding to the data signal for inspection is transmitted to the optical communication section 45.
I will tell this to Department 33. The data signal of this response is transmitted to the light emitting element 34.
is converted into a light beam, transmitted to the light receiving element 37 via the optical fiber cord 49, transmitted to the inspection device 40 via the optical communication section 39, and optical communication is performed between the main box 1o and the inspection tool [I40]. Time-sharing two-way digital communication will be carried out. This two-way digital communication is performed once every 0.5 seconds, and the main box 10
On the side, in order to prevent the light-receiving cable 35 from absorbing disturbance noise, when the same data signal is received three times, the received data signal is determined to be correct b, and the other data signals are determined to be null or null. This prevents malfunctions. Similarly, the light emitting element 34 of the main box 10 sends a response y'-even signal to the inspection device 140 once every 0.5 seconds. The inspection device 40 analyzes the data signal responded from the data processing unit 33 in the main box 10, and lights and motors the light emitting diodes 45 corresponding to the inspection data signal. When the light emitting diode A-45 lights up, it can be g* determined that the main box 10 is operating normally with respect to the data signal for that inspection. By performing this operation in order, all functions downstream of the data transmitter/receiver 31 of the main box 10 can be inspected.
When it is determined that all functions are completely normal, the parts other than the data processing unit 32, that is, the data transmitter/receiver 3
It can be determined that a failure has occurred in part 1, and the main box 10 will be repaired and adjusted. - Bidirectional communication of data signals by the above-mentioned inspection device 40 is performed using light beams and is electrically insulated, making it difficult for electrical problems to occur and allowing safe inspection. . Since the present invention is configured as described above, when inspecting the terminal device, bidirectional data communication is performed between the inspection device and the terminal device without disassembling the terminal device and impairing the eavesdropping prevention function. This allows each function of terminal i*iii to be tested individually.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing the outline of a conventional CA TV system, Fig. 2 is a block diagram showing the internal configuration of a terminal device, Fig. 3 is a perspective view showing the external appearance of the inspection device, and Fig. 4 FIG. 2 is a perspective view showing the relationship between the back of the main box of the terminal device and the plug of the inspection device. 1...Center, 3,6.9...Couple, 28.
...Terminal device, 34.38...Light emitting element, 3! +,
37... Light receiving element, 36... Plug, 40... Inspection device, 47.48... Insertion leg. Patent Applicant Pai A-A Stock Attorney Patent Attorney Nobuo Kiyoshi Udo Patent Attorney Mura 11 Shin Emi β Yu〕 2 2 Otsu

Claims (1)

[Claims] A CATV system that connects a center and a large number of terminal devices with a cable and can perform two-way communication between the center and the terminal devices, in which a light emitting element and a light receiving element are provided inside the terminal device. An inspection hole communicating with the outside of the IJ terminal device is opened at a position facing the light emitting element and the light receiving element, and an insertion leg to be inserted into the inspection hole is protruded from the plug connected to the inspection device, and an insertion leg is inserted into the insertion leg. By inserting an optical fiber cord into the plug, placing a light emitting element and a light receiving element facing each other at one end of the optical fiber cord inside the plug, and inserting the insertion leg of the plug into the inspection hole, the terminal and the inspection device can be connected through optical communication. An unexplored inspection mechanism in a CATV system, characterized in that terminal devices are inspected through bidirectional data communication.