JP2002330456A - Digital distribution frame device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the workability of wiring in the vicinity of the frame by unifying kinds of input output signal wires to the frame device into one kind. SOLUTION: Coaxial terminals 13 to which coaxial lines 12 can be connected are placed above a printed wiring board 11 fixed to a rack and connectors 14, 15 acting like measurement points in rewiring or signal monitoring are placed in the middle in two rows, and jumper wires 16 interconnects the connectors 14, 15. A conversion means 17 that converts a balance signal received from a low frequency device through the coaxial lines 12 into an unbalance signal is placed under the connectors 14, 15. Then terminals used to transmit the balance signal are placed under the conversion means and pair lines 18 leading to a high frequency device are connected to the terminals.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital distribution frame device, and more particularly, to a digital distribution frame device which mediates signal lines connected between communication devices such as an optical communication system.

In an optical communication system, a communication device including a multiplexing device is connected between an analog exchange or a digital exchange and an optical communication network. The communication device is configured to be divided according to a frequency to be handled, that is, a predetermined transmission speed. Each communication device is generally mounted on one housing or shelf, and these housings or shelves are installed on a frame or a rack.

[0003]

2. Description of the Related Art In a communication apparatus, a large number of electronic circuit boards are detachably mounted. The housing of the communication device is provided with a plurality of shelves, and guide members are provided on upper and lower walls of each of the shelves along a direction in which the electronic circuit board is inserted and removed. The electronic circuit board is mounted on the shelf of the housing by inserting it along the guide member. At this time, an electrical connection is made with the back wiring board provided behind the shelf. That is, connectors are provided on the electronic circuit board side and the back wiring board side, respectively. The connectors are fitted to each other. By the mechanical connection between the connectors, each electronic circuit board establishes electrical interconnection via the back wiring board. It has gained.

On the other hand, the electronic circuit board needs to input and output signals and the like to and from other electronic circuit boards in the electronic equipment or to external electronic equipment. For the connection, the connector to which the intra-office cable is connected is fixed to the frame, a case called a block with a small back wiring board is fixed at that position, and the electronic circuit board is mounted on that block. The electrical connection between the external connection connector provided on the electronic circuit board and the connector fixed to the frame is obtained.

Further, some electronic circuit boards of communication devices, for example, power supply packages are duplicated for redundant operation or improved reliability. Will need to be replaced. When the number of lines is increased, for example, an electronic circuit board is newly added. As described above, when replacing or adding an electronic circuit board, an operation of removing the electronic circuit board from the connector or fitting the electronic circuit board to the connector is required.

[0006] When such an electronic circuit board is inserted or removed, the voltage of the power supply may be temporarily reduced. For example, if parallel operation is performed using a power supply package and a power supply protection package as power supply packages, both the power supply current package and the power supply protection package bear half the load current, If, for example, the current power supply package is pulled out of this state, the power supply standby package needs twice the load current as before. In such a case, the DC / DC converter of the power supply backup package controls so as to flow twice the load current, but this causes a time delay, and the voltage may drop momentarily. Due to this momentary voltage drop, the package on the load side may not function properly.
As a result, a line error occurs, and a poor quality line is provided. Similarly, when adding a load-side package, a very large inrush current flows in the package in a short time, which may cause a momentary drop in the power supply voltage and a line error. is there. For this reason, conventionally, a large-capacity bypass capacitor is directly connected to the sheet connector on the back wiring board for the power supply active package and the power supply reserve package by soldering to absorb such a sudden change in the power supply voltage. I am trying to do it.

[0007] Further, the communication apparatus is divided according to the frequency to be handled, for example, 2 Mb / s (megabit / second).
A device that handles primary group velocities up to 8 Mb / s, for example a device that handles tertiary group velocities up to 34 Mb / s, for example a device that handles quaternary group velocities up to 140 Mb / s, And devices that handle quaternary group speeds or higher. Connections between these devices can be made directly, but in the case of electrical signal connections, digital and
The connection is generally made via a distribution frame (hereinafter abbreviated as DDF) device.

The reason for using the DDF device is as follows. In other words, if the maker is different for each device, the connector, terminal, or line type of the wiring connection often does not match, and an intermediary point for matching these is required. If the installation time is different for each device, it is necessary to provide an intermediary point for separating the wiring for each device in order to improve workability. If wiring replacement occurs after installation, redoing the formed wiring requires a great deal of man-hour and cost, and therefore, an intermediary point that can be easily replaced with a jumper wire or the like is required. Since the signal line connection of the apparatus is often made on the back side, when monitoring signals during site adjustment and maintenance, it is necessary to work from the front side instead of the back side. Therefore, the DDF device has a function of changing wiring using a jumper wire and a signal monitoring function, and is a necessity for a communication device.

DDF devices are roughly divided into low-frequency 7
DDF device for 5Ω, DDF device for low frequency 120Ω,
There are three types: high frequency DDF devices. The DDF device for low frequency 75Ω and the DDF device for high frequency are used for connection with an unbalanced coaxial line, and the DDF device for low frequency 120Ω is used.
The device is used for connection with balanced pairs. As described above, even at the same low frequency, there are two types of customer interfaces: a 75Ω system and a 120Ω system.

[0010] In the DDF device for low frequency 75Ω, since the input / output signal line and the jumper line are coaxial, the area occupied by the coaxial connector is large, and it cannot be made compact. In addition, devices that handle low-frequency input / output signals require two types of connectors, such as a flat connector for connecting a paired wire, and a coaxial connector for connecting a coaxial line. However, if two types of connectors are mounted on the device, The connector housing area becomes large, and the device itself becomes large. For this reason, in the conventional DDF device, the connector of the device connecting portion is a flat connector 1 of a wrapping type.
Since the wiring from the DDF device for low frequency 120Ω is a pair wire, it is wrapped and connected to the connector of the device as it is, and the wiring from the DDF device for low frequency 75Ω is coaxial, so the coaxial line Wiring to the vicinity of the connector, terminal processing with coaxial / single wire conversion parts, conversion into two single wires, wrapping connection of the two single wires to the connector of the device, or impedance conversion function of 75Ω / 120Ω inside the device And the switching is set in accordance with the impedance of the wiring.

[0011]

However, in the case of a DDF device, especially a 75Ω system, which connects the devices, a large cable space is required because the coaxial cable is wired to the vicinity of the device, and the number of coaxial lines is large. In addition, coaxial / single-wire conversion processing is required before connecting to the equipment connector, so workability at the time of wiring is poor, and if an inexperienced local worker performs the conversion processing, it may cause a loose contact failure. ing. Devices that handle low frequency input / output signals
Since there are two types of interfaces, 75Ω and 120Ω,
An impedance conversion function is required in the device. Furthermore, since the connecting wires to the low frequency 75Ω DDF device are all coaxial, the area occupied by the coaxial line is large.
The number of accommodated lines is reduced due to restrictions on mounting space.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described circumstances, and is directed to a device that handles low-frequency input / output signals by unifying the type of input / output signal lines to the device into one. It is an object of the present invention to provide a DDF device in which the workability of wiring in a computer is improved.

[0013]

FIG. 2 is a block diagram showing the principle of the present invention for achieving the above-mentioned object. FIG. 2 is a front view of a digital distribution frame device which mediates signal lines connected between communication devices. FIG.

A printed wiring board 11 fixed to a rack is provided with a coaxial terminal 13 to which a coaxial cable 12 can be connected at a position above the printed wiring board 11, and a center for rewiring or monitoring signals when monitoring signals. Connectors 14, 1
5 are arranged in two rows, and between them are wired by jumper lines 16. Below this, there is provided a conversion means 17 for converting a balanced signal received by the coaxial line 12 from the low-frequency side device into an unbalanced signal. A terminal for transmitting a balance signal is provided below the conversion means, and a pair wire 18 to the high frequency side device is connected.

According to the above-described means, the digital distribution frame device has the conversion means 17 for converting the unbalanced signal into the balanced signal, so that the type of the input / output signal line to the high-frequency side device becomes a pair line. Unified and easy to connect signal lines to the high-frequency side device,
Mounting space is reduced.

[0016]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a view of a communication device as viewed from the back. This communication device has a shelf 1 mounted on an open rack, and an electronic device mounted on the shelf 1 having an external line connector 2 and a power connector 3. Circuit board 4
And a back wiring board 6 having a sheet connector 5 connected to the power supply connector 3 of the electronic circuit board 4 and provided on the back surface of the shelf 1. On the back surface of the shelf 1, a back wiring board 6 for electrically connecting the electronic circuit boards 4 is provided, and further, when the electronic circuit board 4 is inserted from the front of the shelf 1, the rear end portion is provided. The shrouds 41, 42 and 43 for holding the external line connection connector 2 are fixed.

Further, the communication device includes a back wiring board mounting connector 7 electrically connected to a power supply line of the back wiring board 6, and includes a connector fitted with the back wiring board mounting connector 7 and a bypass capacitor. A bypass capacitor module 8 is further provided, and the bypass capacitor is configured to be replaceable in a plug-in manner.

FIG. 2 is a front view of a digital distribution frame device that mediates signal lines connected between communication devices. A printed wiring board 11 fixed to a rack has a printed wiring board 11 above it. A coaxial terminal 13 to which the coaxial cable 12 can be connected is provided at a position, and connectors 14 and 15 serving as measurement points when rewiring or monitoring a signal are arranged in two rows in the center. It is wired by a jumper line 16. Below this, there is provided a conversion means 17 for converting a balanced signal received by the coaxial line 12 from the low-frequency side device into an unbalanced signal. A terminal for transmitting a balance signal is provided below the conversion means.
Is connected.

Since the digital distribution frame device has the conversion means 17 for converting an unbalanced signal into a balanced signal, the types of input / output signal lines to the high-frequency side device are unified to a pair line, and the high-frequency side device This facilitates the connection of the signal lines, thereby reducing the mounting space.

FIG. 3 is a diagram showing an example of a transmission system to which the present invention is applied. In this figure, reference numeral 20 denotes an analog exchange to which a telephone line is connected, 21 denotes a digital exchange for data communication, 22 denotes a multiplexer for multiplexing up to a transmission speed of 2 Mb / s. The switch 21 is connected to a digital distribution frame (DDF) device 23.
Between this DDF device 23 and the next DDF device 24,
Multiplexers 25, 2 for multiplexing up to a transmission rate of 8 Mb / s
6 are connected. The optical terminal unit 27 is connected to the DDF device 24 and is connected to an optical communication line of 8 Mb / s. A multiplexing device 2 for multiplexing up to a transmission rate of 34 Mb / s is provided between the DDF device 24 and the next DDF device 28.
9 is connected, and a DDF device 23 and a DDF device 28
A multiplexing device 30 for multiplexing from 2 Mb / s to 34 Mb / s is connected between the two. The DDF device 28 includes:
Optical terminal equipment 31 connected to 34 Mb / s optical communication line
Is connected. Further, the DDF device 28 and the next DD
Three multiplexers 33, 34, 35 for multiplexing up to a speed of 140 Mb / s are connected to the F device 32. Further connected to the DDF device 32 are a 140 Mb / s optical terminal device 36, a radio device 37, and a multiplexing / optical terminal device 38 for multiplexing up to a higher speed, for example, 565 Mb / s, and converting it to an optical signal. Have been.

In this communication device, multiplexing devices 25, 2
6, 29, 30, 33, 34 and 35 and the optical terminal units 31 and 36 are each completed by one electronic circuit board, and the terminals of the input / output signal cables are connected to each electronic circuit board. It is assumed that it can be introduced directly to

FIG. 4 is a diagram showing an embodiment of the communication device. In this figure, the communication device is viewed from the back, and the electronic circuit board mounting shelf 1 is fixed to a shelf mounting rack 40. On the back surface of the shelf 1, a back wiring board 6 for electrically connecting the electronic circuit boards 4 is provided, and further, when the electronic circuit board 4 is inserted from the front of the shelf 1, the rear end portion is provided. Shrouds 41, 42 for holding the external line connector 2
43 is fixed.

On the back side of the back wiring board 6, a power receiving terminal 44 for receiving power supply from outside and a back wiring board mounted connector 7 to which a connector mounted on a bypass capacitor module are fitted are installed.
On the front side, a sheet connector 5 that fits with the power supply connector 3 mounted on the rear end of the electronic circuit board 4 is mounted. The power supplied through the power receiving terminal 44 is supplied to the electronic circuit board 4 through the sheet connector 5 of the back wiring board 6. In addition to the power supply line, a line for an alarm signal and a microcomputer bus are also wired to the back wiring board 6. An alarm signal output connector 45 is provided on the front side of the back wiring board 6 to take out an alarm signal to the outside. If a failure occurs in a certain electronic circuit board 4, the alarm signal is output. Via an output connector 45, for example, an overhead lamp provided on another shelf mounted on the same rack 40 is turned on.

Intra-office cable 46 for connection between external electronic devices
Is introduced into the vicinity of the shelf 1 mounted on the open rack 40 using the groove on the side surface of the open rack 40. The tip of the intra-station cable 46 is the open rack 4
0, cross over the side plate on the back side, pass through the back surface of the shelf 1, and be mounted on the shelf 1
It is led to 3.

FIG. 5 is a diagram showing a connection relationship between the electronic circuit board and external lines. According to this figure, the shrouds 41, 42, 43 mounted on the back of the shelf 1 are changed according to the type of the external line connection connector 2 of the electronic circuit board 4 mounted on the shelf 1. In this embodiment, the shrouds 41, 42, and 43 merely mechanically hold the external line connection connector 2 and do not perform electrical relaying. However, relaying may be employed. Therefore, the shrouds 41, 42, 43 serve as a fixing function of the board when the electronic circuit board 4 is mounted and the coaxial connector 4 of the intra-office cable 46.
7 and the flat connector 48.

Shelf 1 of shrouds 41, 42, 43
Can be attached to and detached from the back of the shelf 1, and the coaxial connector 47 and the flat connector 48 connected to the intra-office cable 46 can be attached to and detached from the shrouds 41, 42, and 43 from the back of the shelf 1. Has become.

In the preferred embodiment, three types of shrouds 41, 42, 43 are provided. That is, in the transmission system of FIG. 3, a multiplexer 30 for increasing the transmission speed from 2 Mb / s to 34 Mb / s by 16 times is taken as an example.
The multiplexer 30 has a pair of input and output lines on the low-speed device side and a coaxial line on the high-speed device side, and accommodates one 16-channel system. First, on the low-speed device side, two signal lines are required for sending and receiving for each channel, so that a total of four signal lines are required, and a total of 64 signal lines are required for 16 channels. If a 36-pin connector is used as the external line connector 2 of the electronic circuit board 4, two connectors are required, and two 16-pair cables are required. On the other hand, the high-speed device requires two coaxial cables for sending and receiving. Therefore, as the electronic circuit board 4, a shroud 41 having an opening for guiding two flat connectors and two coaxial connectors is used.

The transmission rate is increased from 2 Mb / s to 4 times 8 Mb / s.
The multiplexing devices 25 and 26 for s include two 4-channel systems. The signal line is
4 (channels) x 4 (lines) x 2 (systems) = 32, which requires only one cable of 16 pairs. On the high-speed device side, two coaxial cables are required since two systems are required for sending and receiving. Therefore, this includes 1
A shroud 42 having openings for guiding the flat connectors and the four coaxial connectors is used.

Multiplexer 2 for multiplexing the transmission speed four times
In 9, 33, 34 and 35, four coaxial connectors are required on the low-speed device side and one on the high-speed device side, and a total of 10 coaxial connectors are required for sending and receiving. Optical terminal equipment 26, 30, 35
Then two are required for sending and receiving. Further, a switch device for switching a multiplexing device and an automatic protection switching control device for controlling the switch device require six and twelve coaxial cables. Therefore, in an electronic circuit board equipped with these functions, a maximum of 12 coaxial cables are required, and a shroud 43 having an opening for guiding 12 coaxial connectors is commonly used.

FIG. 6 is a view showing another embodiment of the shroud. The shroud 49 in this example has two openings 50 for guiding a flat connector for a pair wire, and twelve openings 51 for a coaxial connector, and these openings 50 and 51 are arranged in a line. Have been. By employing the shroud 49, the shape of the shroud can be unified to one type. In this case, one type of connector housing accommodating the external line connection connector 2 of the electronic circuit board may be used.

FIG. 7 is a view showing still another embodiment of the shroud. The illustrated shroud 52 has two openings 50 for a paired flat connector and twelve openings 51 for a coaxial connector. Here, the two openings 50 and two openings 51 and the remaining ten openings 5
1 and 2 are arranged in two rows. By employing the shroud 52, the shape of the shroud can be unified to one type.

FIG. 8 is a diagram showing a power supply circuit of the communication device. In this figure, two power supply packages 4a, 4b and a plurality of load side packages 4c, 4d, such as a multiplexer, are provided as electronic circuit boards mounted on the shelf 1.
, 4n are shown. In one shelf 1, two power supply packages 4a and 4b having the same configuration are mounted as power supply active and power supply backup packages in consideration of redundant operation of the office power supply, and are operated in parallel. Both of these power supply packages 4a and 4b normally bear half the load of power, and if one of them fails, the remaining power supply package will cover the full load of power. Therefore, these power supply packages 4a, 4b having the same configuration
Has enough power capacity to drive all of the load-side packages 4c to 4n.

The power receiving terminal 44 is connected to the power supply package 4 a via the sheet connector 5 of the back wiring board 6.
4b. The power supply packages 4a and 4b are DC / DC converters 4aa and 4 for converting, for example, a voltage of -48 volts received from a power receiving terminal into a voltage of ± 5 volts.
ba. The voltage output terminals of the power supply packages 4a and 4b are connected to power supply lines of ± 5 volts on the back wiring board 6, and further connected to the sheet connectors 5 for the load side packages 4c to 4n.
A bypass capacitor module 8 is also connected in parallel to the power supply lines on the load side of the power supply packages 4a and 4b. The bypass capacitor module 8 is detachably connected to the load side power supply lines of the power supply packages 4a and 4b via the back wiring board mounted connector 7.

FIG. 9 is a diagram showing details in the vicinity of the mounting position of the power supply package. Although there is no limitation on the mounting position of the load side package, according to this figure, only the position of the sheet connectors 5a and 5b for the power supply packages 4a and 4b is determined, and on the back wiring board 6 near this position. The back wiring board mounting connector 7 and the power receiving terminal 44 are centrally arranged. In particular, the back wiring board mounting connector 7 is arranged at a position as close as possible to the sheet connectors 5a and 5b for the power supply packages 4a and 4b, that is, the shortest distance to the load-side output for the power supply packages 4a and 4b.

FIG. 10 is a diagram showing details of the bypass capacitor module. Bypass capacitor module 8
Is a connector 8a fitted to the back wiring board mounting connector 7, two polar electrolytic capacitors 8b and 8c for positive and negative power supplies, and a printed circuit board 8 on which these are mounted.
d and a case 8e for accommodating them. The connector 8a and the capacitors 8b and 8c are mounted on the same surface of the printed circuit board 8d, and the two capacitors 8b and 8c are arranged with the connector 8a interposed therebetween.

FIG. 11 is a diagram showing a cross section when the bypass capacitor module is mounted. According to this figure, after the back wiring board back cover 50 is mounted on the shelf 1 from the back surface of the back wiring board 6, the bypass capacitor module 8 passes through the opening provided in the back wiring board back cover 50. It is mounted on the connector 7 mounted on the back wiring board. In addition to the coupling of the connector 8a of the bypass capacitor module 8 and the connector 7 mounted on the back wiring board, the case 8e of the bypass capacitor module 8 is provided with a necked screw 8f and a retaining washer 8g. The case 8e is fixed to the back wiring board back cover 50 by screwing a screw 8f into a tap hole provided in the back wiring board back cover 50.

Since the bypass capacitor module 8 has a plug-in type structure, it is easy to replace the capacitor during the life of the capacitor, and it is possible to simultaneously replace the two capacitors 8b and 8c for the positive power supply and the negative power supply. Will be possible. When the capacitors 8b and 8c are mounted on the printed circuit board 8d, the capacitors 8b and 8c are housed in the space between the back wiring board back cover 50 and the back wiring board 6 on the same surface as the connector 8e. Therefore, the bypass capacitor module 8 has a low profile in which the height of the case 8e, that is, the amount of protrusion from the back wiring board back cover 50 to the rear is small.

Since the capacitors 8b and 8c are mounted on the power supply line on the load side of the power supply packages 4a and 4b, voltage fluctuations occurring on the power supply lines can be reduced.
That is, at the time of replacement due to a failure, the power supply package 4
It is necessary to pull out a or 4b, but at this time, the remaining power supply package 4b or 4a must be controlled to twice the output current as before. However, since the DC / DC converter cannot respond instantaneously, a shortage of current is supplied from the capacitors 8b and 8c until the output voltage is settled. The magnitude of the voltage fluctuation is minimized. Conversely, when a power supply package is added for parallel operation,
The / DC converter can suppress voltage fluctuations until the supply current is controlled to be halved.

Similarly, in the load-side packages 4c to 4n, it is necessary to replace the package due to the occurrence of a failure or to change the line interface or to insert and remove the load-side package in connection with the extension work. At this time, an instantaneous voltage drop occurs due to a sudden change in the load current, but the presence of the capacitors 8b and 8c eliminates the instantaneous voltage drop, thereby preventing a line error due to a malfunction of the load side package. Will be done.

FIG. 12 is a circuit diagram showing an example of the DDF device. This DDF device takes up a lot of mounting space.
It is applied to inter-device connection in which a large number of Ω-based coaxial cables are accommodated and passed to a high-frequency device having no mounting space by a pair wire.
For example, the DDF device 23 in the example of the transmission system in FIG. 3 can be used, and the interface with the low-frequency device is a 75Ω coaxial line.

In FIG. 12, reference numeral 60 denotes a low frequency side device, 70 denotes a low frequency 75Ω DDF device, and 80 denotes a high frequency side device. The low frequency 75Ω DDF device 70 includes a coaxial terminal 13 for receiving the coaxial line 12 from the low frequency side device 60.
have. The coaxial terminals 13 are provided in accordance with the number of accommodated lines. For example, if there are eight lines, the input lines i1 to i8
And 16 input / output lines for the output lines o1 to o8. In the example shown in the figure, eight lines are regarded as one system,
This is called the four systems SYS1, SYS2, SYS3, SY
S4 is provided. Each coaxial terminal 13 is connected to a 32-pin flat connector 14a. The flat connector 14a is a portion to which the connector of the jumper wire 16 is connected, and is also a measurement point of the low-frequency device side signal to which the connector of the measuring cable used for maintenance or the like is connected. A portion connected to the connector at the other end of the jumper line 16 is a 32-pin flat connector 15a, and this flat connector 15a is also a measurement point of the high-frequency device side signal. The connection position between the flat connectors 14a and 15a and the connector of the jumper wire 16 can be freely changed, so that the DDF device 70 for low frequency 75Ω also has a function of wiring replacement.

The flat connector 15a is connected via a transformer 17a for converting a balanced signal / unbalanced signal to 32.
A pin flat connector 71 is connected. As for the channel on the side received from the low frequency side device 60, an earth setting terminal 72 set according to customer specifications is provided on the flat connector 15a side of the transformer 17a.
For the channel on the transmission side to 0, capacitors 73 and 74 for correcting waveform deterioration are connected to the signal input / output terminals of the transformer 17a.
Are connected in parallel. DD for low frequency 75Ω
The connection of the F device 70 to the high frequency side device 80
Flat connector 71 and high-frequency side device 8 of DDF device 70 for Ω
This is carried out by the pair wire 18 connecting the flat connector 81 of the "0". In this example, the pair wire 18 is a single cable with 16 pairs for eight lines, and the flat connectors provided at both ends are 32 pins.

FIG. 13 is a diagram showing an example of mounting the DDF device on a rack. This figure shows a state in which the DDF device 70 for low frequency 75Ω is attached to the shelf mounting rack 40 from the front, and four 8-line systems are mounted. The coaxial terminals 13 are arranged in two rows of 32 each above the front side of the printed wiring board 11. Jumper wire 16
The flat connectors 14a and 15a to which these connectors are connected are also mounted on the front side of the printed wiring board 11 by four.
Between the mounting positions of the flat connectors 14a and 15a, there are 64 transformers 17a and 32 ground setting terminals 72 and 6
Four capacitors 73 and 74 are mounted on the front side of the printed wiring board 11, and four flat connectors 71 for connection to the high-frequency side device are mounted on the back side of the printed wiring board 11. Therefore, the coaxial terminal 13 of the coaxial line 12
The connection to the flat connectors 14a and 15a and the connection of the measurement cable to the flat connectors 14a and 15a can be performed from the front side.

As in the above example, when the number of lines of the low-frequency side device 60 is 8 lines × 4 systems, the number of coaxial lines 12 and the number of jumper lines 16 from the low-frequency side device 60 are respectively It becomes 64. For this reason, if only the cable connection on the high-frequency device side is made a flat connector, the coaxial terminal 13 for connecting the coaxial cable 12 and the connector for connecting the jumper cable 16 are combined, resulting in a total of 192 connectors, which is a huge mounting space. Need. For this reason, the jumper wire 16 is not coaxial, but is a shielded wire and both ends are flat connectors, so that the portion to be connected to the coaxial wire is 64 coaxial terminals 13.
It is only necessary to mount the jumper connector in a small space.

The jumper wire 16 uses a shield wire having an impedance of 75Ω and a core wire and a drain wire twisted like a pair wire since a normal shield wire causes signal deterioration. A two-pin flat connector is provided. Of course, this shield wire is also employed in a measurement cable connected to the flat connector 14a or 15a during measurement.

[0046]

As described above, according to the DDF device of the present invention, the impedance conversion function originally provided on the high-frequency device side is transferred to the DDF device, and a jumper line of 75Ω is used.
By using the shielded wire, the total cost can be reduced, the floor space of the transmission system can be reduced, and the workability of construction work can be improved. That is, the impedance of the high frequency side device is 120Ω
Therefore, the impedance switching function in the device is not required, and the cost of the device can be reduced. Wiring to the high-frequency side device is connected by a connector. Because it can be used, the number of cables is reduced, wiring space is saved, construction workability is improved, and the use of shielded jumpers reduces coaxial wires, reducing mounting space and reducing the number of accommodated lines. Can be increased.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a communication device.

FIG. 2 is a principle configuration diagram of a DDF device of the present invention.

FIG. 3 is a diagram illustrating an example of a transmission system to which the present invention is applied.

FIG. 4 is a diagram illustrating an embodiment of a communication device.

FIG. 5 is a diagram showing a connection relationship between an electronic circuit board and an external line.

FIG. 6 is a view showing another embodiment of the shroud.

FIG. 7 is a view showing still another embodiment of the shroud.

FIG. 8 is a diagram showing a power supply circuit of the communication device.

FIG. 9 is a diagram showing details in the vicinity of a power supply package mounting position.

FIG. 10 is a diagram showing details of a bypass capacitor module.

FIG. 11 is a diagram showing a cross section when a bypass capacitor module is mounted.

FIG. 12 is a circuit diagram illustrating an example of a DDF device.

FIG. 13 is a diagram illustrating an example of mounting a DDF device to a rack.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Shelf 2 Connector for external line connection 3 Connector for power supply 4 Electronic circuit board 5 Sheet connector 6 Back wiring board 7 Connector mounted on back wiring board 8 Bypass capacitor module 11 Printed wiring board 12 Coaxial line 13 Coaxial terminal 14, 15 Connector 14a, 15a Flat Connector 16 Jumper wire 17 Conversion means 17a Transformer 18 Pair wire

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Tsutomu Takahashi 4-1-1, Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Prefecture Inside Fujitsu Limited (72) Inventor Hirohito Kadoya 4-chome, Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Prefecture No. 1 Fujitsu Limited (72) Inventor Junichi Hayama 4-1-1 Kamikodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture F-term within Fujitsu Limited (reference) 5K073 AA03 EE05 GG03 GG07 GG08 JJ02 JJ14 JJ15

Claims (4)

[Claims] 1. A digital distribution frame device for mediating a signal line from a low-frequency device, a conversion means for converting an unbalanced signal received by a coaxial line from the low-frequency device into a balanced signal. A digital distribution system characterized by having
Frame device. 2. The digital distribution frame device according to claim 1, wherein said conversion means is disposed between a signal measuring point and a high frequency side device. 3. A jumper line (1) connecting between a signal measurement point of the low-frequency device and a signal measurement point of the high-frequency device.
6. The digital distribution frame device according to claim 1, wherein 6) is a shielded line having the same impedance as the coaxial line and terminated by a flat connector. 4. A digital distribution frame device for mediating a signal line from a low-frequency device, wherein a conversion means for converting an unbalanced signal received by a coaxial line from the low-frequency device into a balanced signal is used. A digital distribution frame device characterized in that the impedance viewed from the high-frequency side device is unified into one type.