JP3418211B2 - Equalizer identification device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an equalizer for identifying an equalizer installed in a relay amplifier used in a high-frequency analog transmission system, for example, a CATV system. Related to the device. 2. Description of the Related Art Conventionally, in a CATV system, as shown in FIG. 3, a center 1 having a monitoring control function in the system is provided.
0 and each of the sub-centers 11 to which a plurality of subscriber terminal equipments 12 are connected by a transmission line 13 such as a coaxial cable or an optical fiber cable. 12 transmits necessary video signals and various electric signals. Further, a plurality of relay amplifiers 14 are connected to the transmission path 13, and compensate for losses such as attenuation and distortion of each data signal on the transmission path 13, and transmit each data signal to the sub-center 11. Was. As shown in FIG. 4, the relay amplifier 14 includes an equalizer 15 such as an attenuator (ATT), an equalizer (EQ), or a quasi line (BON) for equalizing a loss of a data signal due to the transmission line 13 or the like. And an amplifier 16. After installing the transmission line, these equalizers 15 measure the input arrival level of each relay amplifier 14, and select an appropriate type and equivalent amount from the measurement results.
The transmission path 13 and the amplifier 16 were connected by a plug-in method. In the above relay amplifier, when the necessity of changing the equivalent amount of the equalizer arises due to the route change after the system construction, or when the maintenance including the trouble of the transmission line is performed, the type of each equalizer is used. And recognizing the equivalent amount, the equalizer was replaced with an appropriate one. However, since the relay amplifier has no means for recognizing the type of the equalizer in advance, the lid of the relay amplifier is opened each time the relay is replaced, and the type of the equalizer and the like are removed. Must be checked visually. However, the number of relay amplifiers installed per facility is as large as several hundreds, and the installation area is as large as several kilometers. Therefore, a great deal of labor is required to check the types of equalizers. was there. SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide an equalizer discriminating apparatus capable of easily recognizing the type and equivalent amount of an equalizer. In order to achieve the above object, according to the present invention, a relay amplifier for amplifying a signal such as a television signal transmitted in a transmission system is provided, and various characteristics of the signal are compensated. Device for identifying equalizers
An identification circuit incorporated in a price unit and holding identification information for specifying the type and equivalent amount of the equalizer; and the identification circuit.
A status monitor for reading the identification information held by the
The status monitor reads out the identification information
It is specially equipped with a communication function for sending data into the transmission system.
It is a sign. Therefore, the type and equivalent amount of the equalizer
Provides an equalizer identification device that can easily recognize
can do. An identification circuit as identification means for identifying the type and equivalent amount of an equalizer is added to a relay amplifier as an amplification unit.
Enables recognition of equalizers by status monitor, center, etc. An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a block diagram showing an embodiment of an equalizer identification apparatus according to the present invention. In the figure, the equalizer 15, so as to enable the plug-in relay amplifier 14 is a circuit configuration in a predetermined case 17, the input terminal T1 and the output terminal T 3, is connected to the transmission line 13 and the amplifier 16 . Incidentally, T 2 is a terminal for grounding. Therefore, in the present embodiment, an identification circuit 18 for identifying the type and equivalent amount of the equalizer 15 is provided in the case 17 and when plugged into the relay amplifier 14, the terminals T4, Via T5, a status monitor (hereinafter, referred to as a remote monitor / control unit in the relay amplifier 14)
It is called "STM". ) 20. Identification circuit 18
Are a constant-voltage power supply 18a connected in series and a fixed resistance 18b having a fixed resistance value, and the power supply 18a and the fixed resistance 18
b and a resistor 18c connected in parallel with
Connected to TM20. The fixed resistor 18b and the resistor 18c form a voltage dividing circuit. In the present embodiment, the equalizer 15 is identified by changing the resistance value of the resistor 18c according to the type and equivalent amount of the equalizer 15. That is, the identification circuit 18
Then, the DC voltage from the power supply 18a is changed according to the ratio between the resistance values of the fixed resistor 18b and the resistor 18c, and the voltage is applied to the STM 20 provided inside the relay amplifier 14. The STM 20 reads the applied voltage, identifies the connected equalizer 15 according to the value, and transmits the result as a data signal to the center 10 via the transmission line 13. Having. In the present invention, as the power supply 18a and the fixed resistor 18b, a constant voltage circuit and a fixed resistor provided in the relay amplifier 14 can be used. Further, the STM 20 can also have only a conversion function of reading the applied voltage, converting the value into a digital signal, and transmitting it as a data signal to the center 10. It is also possible to configure such that the data signal is decoded to recognize the type and equivalent amount of the equalizer. Further, in the present embodiment, it is possible to set the communication function of the STM 20 so that the identification result of the equalizer 15 is transmitted to a nearby sub-center. Thus, the center 10 recognizes the type and equivalent amount of the equalizer based on the received data signal,
The type and the equivalent amount can be displayed on a CRT (not shown) or printed out by a printer or the like.
Therefore, in the present embodiment, an equalizer discriminating circuit is configured by using a voltage division ratio by a resistor or the like, and the value of the resistor is changed according to the equalizer to be used. The type and equivalent amount of the equalizer
It can be easily detected by a TM or center. As described above, according to the present invention, an amplifying unit which is provided in an amplifying unit for amplifying a signal such as a television signal transmitted in a transmission system and which compensates for various characteristics of the signal is provided. In addition, since the identification means for identifying the type and the equivalent amount of the equalizer is provided, the type and the equivalent amount of the equalizer can be easily recognized. In this case, each equalizer can be easily replaced with an appropriate one.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of an equalizer identification device according to the present invention. FIG. 2 is a circuit diagram showing a circuit configuration of an identification circuit shown in FIG. FIG. 3 is a diagram showing a system configuration of a CATV system. FIG. 4 is a diagram showing a configuration of the relay amplifier shown in FIG. [Description of Signs] 10 center 11 sub-center 12 subscriber terminal device 13 transmission line 14 relay amplifier 15 equalizer 16 amplifier 18 identification circuit 20 status monitor (STM)

Claims (1)

(57) [Claim 1] An equalizer discriminating device incorporated in a relay amplifier for amplifying a signal transmitted in a transmission system and compensating various characteristics of the signal . And the type and equivalent amount of the equalizer
An identification circuit for holding identification information for specifying, and a stator for reading the identification information held by the identification circuit
A status monitor , and transmits the identification information read by the status monitor to the
An identification device for an equalizer, having a communication function of transmitting the signal to a transmission system .