DE10209339B4 - Circuit arrangement for operating multiple interfaces in a LAN network and interface - Google Patents

Abstract

circuitry to operate multiple interfaces in a data network, such as a LAN network, wherein the interfaces (1) designed as access points are and the access between the wired data network and a control wireless data network (radio network) and the interfaces (1) cascaded are arranged and the lines (a ... f) of the data cable looped through are, with the power and voltage supply of the other interfaces (1) from the first interface (1) preferably by means of in the data cable existing spare lines (e, f) takes place, thereby characterized in that the first interface (1) is a detection dipole (19) for connection to a transmitter device (2, 3), the data cables present in the data cable (a ... d) connected to the existing spare cables in the data cable (e, f) to select either current or voltage across the data lines or to feed the reserve lines, a the Detektionszweipol (19) connected rectifier (20) and a rectifier (20) downstream supply socket (17) for connecting an external Current or voltage source (24) to supply power or voltage, having.

Description

The The invention is based on a circuit arrangement for operating several Interfaces in a wired data network, in particular a LAN network (Line Area Network), whereby the interfaces as Access Points are formed and access between the wired Control network and a wireless data network, respectively an interface for such a switching arrangement.

When Access points trained interfaces, the information of a LAN network to a wireless standard such as Bluetooth implement and on sending a mobile subscriber are, for example, from the company Red M known. At these access points / interfaces has become However, it proved to be disadvantageous that each with itself a separate power source, i. connected to the usual 220V mains must be in order to enable the operation. Usually done this over a plug-in power supply, the primary side to the 220 V network is connected. On the secondary side the power adapter is connected to the access point and delivers a voltage of 40 volts, which may be found in the access point and the like. rectified and can be processed further.

Out The standardization guideline IEEE 802.3 is also known, the Power supply of the interfaces via the LAN bus (Power over LAN) perform, where here primarily for the signal transmission required four LAN lines / wires of the LAN bus can be used. In The above-mentioned standardization directive was also proposed instead its usually four more, but unused reserve lines LAN cable, which has a total of eight wires, which are thus automatically relocated.

Unfavorable at all known proposals however, that they are individual solutions which are independent can work from each other, but for example, provide no protection against a short circuit. Especially can individual interfaces can not be switched off without all Interfaces of this measure are affected.

A switching arrangement with the features of the preamble of claim 1 is known from WO 99/37047 A1. WO 99/37047 A1 shows a data network with cascaded successive interfaces for connecting a radio network, wherein the power supply of the interfaces from the first interface using existing in data cables spare lines. The first interface can either be designed so that it is powered by the reserve lines with energy or connected via a power cord to the power supply. From the US 6,218,930 B1 is also known to design the power supply of an interface cascade as power over LAN.

task According to the invention, it is a cascade-like switching arrangement behind one another switched interfaces with an improved power supply provide.

These The object is achieved by a switching arrangement according to claim 1. preferred Trainings are in the dependent claims specified.

The inventive circuit arrangement to operate multiple interfaces in a wired data network and has the advantage that the interfaces in the data network are cascadable and the data bus, which is laid, for example, as an eight-core LAN cable, is looped through the connected access points. This can, for example on a 100 Mbit LAN bus several access points work and the use full data rate. It is considered particularly advantageous that the supply current or voltage from the first interface preferably up to the last interface via the existing reserve lines can be looped through. Single power adapters for each interface or access point are no longer required. Only the first interface requires a current or voltage source, which can then be used by the other interfaces. Farther is connected in the supply circuit, a current limiter. As a result, the flowing current can be monitored in a simple manner and if necessary limited or switched off.

When very cheap is considered that the energy supply for the other interfaces by a power or voltage source connected to a supply socket the first interface is connectable. This can, for example also such interfaces are used, with which no own Connection for a separate Voltage source is provided.

A favorable solution is also seen to use for power supply a DC or voltage source, which is preferably designed as a plug-in power supply. Such power adapters are usually inexpensive to obtain in the trade. Since only the first interface needs such a plug-in power supply, of course, for the appropriate Load must be designed, no external supply socket is required for the other interfaces.

A particularly simple embodiment for the current limiter can be realized by a PTC resistor. Through his positive temperature coefficient automatically limits the current, when its temperature increases. Thereby can very effective the power supply and / or downstream components or assemblies from damage protected become.

From Another advantage is that the power supply at the output of the Strombebgrenzers tapped the first interface and using the reserve lines of the LAN cable to an input of a Detektionszweipols another Interface supplied becomes. As a result, the power to the downstream interface controlled and may be limited in the event of a short circuit or be switched off with a circuit part. The power supply is preferably only released again when the short circuit is not more is available. Another advantage is that all interfaces in the chain remain in operation.

The Infeed of current or voltage directly into a detection dipole The first interface has the advantage of being tested can, whether connected to the line an interface such as an access point is, which must be supplied accordingly.

A favorable alternative solution is also seen therein, the power or voltage source with the To connect reserve lines of the data cable and to the input of the detection dipole of the first interface. Thereby can in some cases a loop through the data cable can be simplified.

A more cheap Circuit variant is seen in the power supply via the data bus to lead yourself where the lines are above one and output terminals of the interfaces are looped through.

A advantageous application for the circuitry is used at a LAN access point that after a standard like Bluetooth or the like works. such Interfaces can very flexible and easy to install, especially since they are independently from the usual 220V power line are.

at the interface is considered an advantage that the supply socket is arranged between a rectifier and the current limiter. This is independent from the choice of power supply ensures that always the voltage with the right polarity is applied. Possible damage that could be caused by reverse polarity damage advantageously avoided.

Cheap is continue, the power or voltage source directly to the free To connect reserve lines of the data cable. This can be easy on Way the power supply will be looped through.

For a universal Use of the interface, especially in a LAN bus for the supply additional access points provided output terminals, allowing the installation becomes simpler. In this way can be very easy in the LAN network also install or replace several access points retrospectively.

Four embodiments The invention are illustrated in the drawings and will be described in the following Description closer explained.

1 shows a schematic representation of an interface which is designed as an access point for a LAN network and in which several possibilities for the connection of a current or voltage source are provided,

2 shows a first embodiment of the invention, in which the power or voltage source is connected to a supply socket of the first interface, while the energy for the other interfaces is looped through available spare lines of a LAN cable,

3 shows a second embodiment of the invention, in which the energy is fed via two spare lines of the LAN cable,

4 shows a third embodiment of the invention, in which the energy is fed via the lines of the LAN bus itself and

5 shows a fourth embodiment of the invention, a further modification for the passage of the energy to the other interfaces.

in principle the invention is applicable to any wired or wireless data networks (Radio networks), also applicable to infrared Ba sis, where by an access node, an interface or access point of traffic controlled from one network to the other network.

For better understanding, the inven tion is described using the example of an access point, which is preferably arranged in a LAN network (LAN bus) and controls access to a radio network, for example for the Bluetooth standard.

In 1 First, the structure of an access point 1 explained in more detail with its schematic structure and the various possibilities of energy supply. The access point 1 is operated with a LAN bus.

Typically, a LAN cable uses eight lines or wires, of which four lines a ... d are usually required for the LAN bus. These four lines a ... d are connected to input terminals LAN-in of the access point 1 connected. The remaining four wires of the LAN cable are usually unused as spare wires. For clarity, were in the 1 to 5 of the four reserve lines, however, only the two reserve lines e, f shown, since only these are used for the invention.

The four used LAN lines a ... d are in pairs on two transformers 2 . 3 (Transmitter / Receiver) out and get over two Ethernet ports, for example 6 and two more transmitters 4 . 5 at output terminals LAN-out, where they then as looped lines with another interface 1 can be connected, as will be explained later. This approach has the advantage that in an existing installation of a network, an access point 1 can be simply looped in as another participant. For example, a computer that is already connected to the LAN network can be accessed through the access point 1 For example, with the help of the Bluetooth standard or with another wireless standard, wireless access to a laptop or vice versa.

To control the traffic on the LAN bus is an Ethernet controller 7 provided that filters out the data packets from the LAN network, for this access point 1 and via a USB or V24 interface 9 to an RF part 12 passes. Another controller 7 on the HF part 12 converts the data so that it has an antenna 16 can be sent. For the sake of completeness it should be mentioned that other units like a memory 10 , a JTAG port 8th , an expansion flash, a boot block 14 and a memory 15 are provided. Furthermore, corresponding clocks with 25 MHz, 11.5 MHz and 32 KHz are provided. The units are known per se and therefore need not be explained further.

For the power or voltage supply of this access point 1 There are three options. The first option is called 'Power over LAN supply'. According to the guideline IEEE 802.3, a voltage of 40V is transmitted via the LAN bus on the four transmit and receive lines a ... d. The voltage is at the center tap of the two transformers 2 . 3 decoupled and on a Detektionszweipols 19 guided. The detection dipole 19 checks for an access point 1 is connected and if necessary must be supplied with energy. The detection dipole 19 For safety reasons, they are two protective resistors 18 upstream.

The detection dipole 19 is a rectifier 20 connected downstream, which rectifies the incoming voltage of 40V accordingly. This is followed by a current limiter 21 , which is designed for example as a PTC resistor. He is followed by a switch 22 with which the applied voltage can be switched on or off, for example, if an error or a short circuit has occurred. At the output of the current limiter 21 the voltage across unused reserve lines (e, f) will be the next access point 1 fed. Furthermore, the voltage is applied to a DC / DC converter 23 for example, reduced to 3.3V, which is to reset R of the Ethernet controller 7 is guided.

The current limiter 21 should always respond if in this or a subsequent interface 1 too high power consumption, for example due to a short circuit occurs. Due to the positive temperature coefficient of the current limiter 21 When heated, its volume resistance increases sharply, so that the current is reduced accordingly, regardless of which power source is connected.

The desk 22 The task is to remain high-ohmic until the supply voltage of 40V is applied to the system. Checking for an Access Point 1 can be supplied with energy from the LAN network, is determined according to the IEEE 802.3 with a small voltage. Only then, if it was recognized that an access point 1 is connected, the 40V are switched from a control center (switch) to the LAN cable. Only then may the access point 1 Take energy from the supply, using the DC / DC converter 23 as the last link in the chain 19 ... 23 this voltage into the supply voltage of 3.3V for the controller 7 converts.

Furthermore, there is a supply socket 17 provided, to which a current or voltage source 24 , can be connected, for example, as a plug-in power supply. The supply socket 17 is between the rectifier 20 and the current limiter 21 completed.

As a second option for the electricity or Voltage supply alternatively, the reserve lines e, f of the LAN cable can be used when appropriate connections are led out. The two reserve lines e, f are also protected by two protective resistors 18 to the entrance of the De tektionszweipols 19 guided, so that their voltage can be checked here. The reserve lines 19 are automatically routed to all participants with the LAN cable so that no additional installation work is required. The reserve lines e, f are usually unused, since only four lines are needed for a LAN connection. A second LAN port that could use the spare lines is not installed in practice.

The downstream rectifier 20 ensures the correct polarity of the voltage in the system.

The third way of power or voltage feed is through the aforementioned supply socket 17 given. As a power or voltage source 24 a standard plug-in power supply can be used, which supplies a corresponding DC voltage. The supply socket 17 is designed for this purpose reverse polarity protected. Because of the looped reserve lines e, f several other access points 1 can be connected, is the power adapter 24 for the resulting load to be dimensioned accordingly.

To prevent the power supply 24 its energy can feed backwards into the LAN network, it became at the output of the rectifier 20 connected.

It is intended that an access point 1 is formed as possible, that depending on the assembly option, all three connection options are available to allow universal use.

With reference to the embodiments of the 2 to 5 will supply power to other access points 1 explained in more detail.

3 shows a circuit arrangement in which the first access point 1 at the supply socket 17 with a power adapter 24 is supplied. The power or voltage supply of the three downstream access points 1 takes place via the two reserve lines e, f, wherein the voltage at the output from the current limiter 21 tapped and via the two reserve lines e, f respectively on the detection dipole 19 of the subsequent access point 1 are switched. The active four wires a..d of the LAN bus remain unaffected, as indicated by the arrow connections. In this case, the detection bipole is 19 and the rectifier 20 not in use. The further structure of the access points 1 corresponds to the description too 1 ,

In the second embodiment according to the 3 becomes the first access point 1 supplied via the two reserve lines e, f of the LAN cable, which on the Detektionszweipols 19 are guided. In this case, the detection two poles 19 and the rectifier 20 in operation. The supply socket 17 stays open and unused here. The other access points 1 are supplied via the reserve lines e / f of the LAN cable, as already closed 2 was explained.

A third embodiment of the invention is in 4 shown. Here, the voltage is transmitted via the LAN bus itself. The energy is at the first access point 1 at the transformers 2 . 3 ( 1 ) and at an input of the detection dipole 19 of the downstream access point 1 fed. The following access points 1 are accordingly supplied via the reserve lines e, f, as previously described.

5 shows a fourth embodiment of the invention, a further modification for the passage of energy to the other access points 1 , In this example, the energy is transmitted via the wires a..d of the LAN bus to the center points of the transformers 2 . 3 decoupled, through the access point 1 dragged and then back to the other transformer 4 . 5 guided. The energy is then given again via the wires a..d of the LAN bus, which are connected to the next ac cess point 1 are connected. In this case, only the four lines a..d are needed, the spare cables of the LAN cable remain free.

1

Interface / Access Points

2

exchangers

3

exchangers

4

another transformer

5

another transformer

6

Ethernet port

7

Ethernet controller

8th

JTAG port

9

USB / V24 interface

10

Storage

11

interconnectors

12

RF unit

13

expansion Flash

14

boat block

15

random access memory

16

antenna

17

supply jack

18

protection resistor

19

Detektionszweipol

20

rectifier

21

current limiter

22

switch

23

DC / DC converter

24

Electricity- or voltage source

A..D

Cables / wires of the data cable

e f,

spare lines of the data cable

LAN in

input terminals

LAN out

output terminals

R

reset line

Claims (6)

Circuit arrangement for operating a plurality of interfaces in a data network, for example a LAN network, wherein the interfaces ( 1 ) are designed as access points and control the access between the wired data network and a wireless data network (radio network) and wherein the interfaces ( 1 ) are arranged in cascade and the lines (a ... f) of the data cable are looped through, wherein the power and voltage supply of the other interfaces ( 1 ) from the first interface ( 1 ) takes place preferably with the aid of reserve lines (e, f) present in the data cable, characterized in that the first interface ( 1 ) a detection dipole ( 19 ) for connection to a transmitter device ( 2 . 3 ) connected to data lines (a ... d) present in the data cable, and to the spare lines (e, f) present in the data cable for selectively supplying power or voltage via the data lines or the reserve lines, to the detection terminal ( 19 ) downstream rectifier ( 20 ) and a rectifier ( 20 ) downstream supply socket ( 17 ) for connecting an external power or voltage source ( 24 ) to supply power or voltage has. Circuit arrangement according to Claim 1, characterized in that the interfaces ( 1 ) a current limiter ( 21 ), which in the power and voltage supply of the following interfaces ( 1 ) is switched. Circuit arrangement according to Claim 2, characterized in that the current limiter ( 21 ) is designed as a PTC resistor. Circuit arrangement according to one of claims 1 to 3, characterized in that as an external current or voltage source ( 24 ) A DC or DC voltage source is ver used, which is preferably designed as a plug-in power supply. Circuit arrangement according to one of claims 2 to 4, characterized in that the current and voltage supply at the output of the current limiter ( 21 ) of the first interface ( 1 ) and by means of the reserve lines (e, f) of the data cable to an input of the further interface ( 1 ) is guided. Circuit arrangement according to one of the preceding claims, characterized in that the interfaces is designed as an access point for a LAN bus and transmitting and receiving devices ( 12 . 16 ), which operate according to a standard such as Bluetooth or the like.