JP3492345B2 - LAN tester - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a LAN (Local Ar
ea Network), which belongs to the test equipment that easily performs disconnection, short circuit, polarity check, connection test, reverse connection test, etc.

[0002]

2. Description of the Related Art Conventionally, a relatively small-scale data processing device such as a personal computer was often used alone, but in the recent trend of improving data processing capacity and downsizing. Therefore, in order to make effective use of the accumulated data, for example, a plurality of data processing devices within a specific range such as a company or a department are connected to a network to configure a distributed processing system,
It is common practice to construct a simple network without performing distributed processing.

Such networks are generally called LA
It is called N and is one of the easiest LAN constructions.
There is a combination of a network OS (Operating System) and a peer-to-peer 10BASE2 or 10BASE-T. Of these, 10BASE-T
LAN connection is relatively simple and can be performed on the user side without asking an expert to do the wiring. Therefore, when constructing a LAN based on 10BASE-T, the wiring is often done by the user.

However, although the wiring of 10BASE-T is simple, if there is a wiring mistake, it does not function as a network, and as the scale of LAN increases, the number of cables increases and the wiring becomes complicated. Is coming.
In this situation, for example, when a failure such as a cable break or miswiring occurs, the procedure to find out which cable has the failure is to first attach fold back connectors to both ends of each cable. In addition to connecting, connect a dedicated cable tester including loop resistance etc. and conduct a continuity test for each cable,
A method is used in which the presence or absence of disconnection or miswiring is checked for each cable and the cable in which a failure has occurred is searched for.

[0005]

However, in such a conventional method for searching for a broken cable, it is necessary to connect the folding connectors to both ends of the cable to be tested. Therefore, the folding connector is connected to one end. In order to connect the folding connector to the other end later, it is necessary to follow the cable in which the folding connector is connected to one end. In other words, finding the cable to which the folding connector is connected is a difficult task in complicated wiring, and in the conventional continuity test, finding a fault requires an extremely large amount of labor. Becomes

In addition, the connection work of the folding connector for conducting the continuity test has a problem that it may cause a new obstacle such as a wrong connection or a contact failure. However, there is a problem that the connection confirmation test including the HUB and the like cannot be performed.

An object of the present invention is to solve the above problems and to perform a cable continuity test and a miswiring confirmation test only at one end, and a simple operation test including a HUB and the like.
To provide an N tester.

[0008]

In order to solve the above problems, a LAN tester of the present invention is provided with a pair of transmission terminals (SA, SB) and a pair of reception terminals to which a pair signal line for LAN wiring is connected. A test terminal composed of (RA, RB),
LA including a circuit that can output an input signal by folding it back
A first test circuit that forms a closed circuit by the pair signal line when N and the test terminal are connected by the pair signal line, and detects whether or not the closed circuit is conductive, and
An electronic circuit (1) including a second test circuit that detects the polarity of a signal input from the pair of transmission circuits, a power supply section (E) that supplies DC power to the electronic circuit (1), and the electronic circuit (1). A switching circuit (1a, Q3) for selectively forming an on state and an off state for operating the circuit (1) as the first test circuit or the second test circuit; The test circuit of FIG.
The first unidirectional element (LY1) which conducts electricity when B) is conducted through the LAN and the pair signal line and the switching circuit (1a, Q3) is in the on state to clearly indicate the energized state.
And the pair of transmission terminals (SA, SB) are connected to the LAN.
And the switching circuit (1
a, Q3) has a second unidirectional element (LY2) that energizes to clearly indicate the energized state when the switching circuit (1a, Q3). )
The first transistor (Q2) and the second transistor (Q4), which are in the off state when they are in the on state and are in the on state when they are in the off state, are connected in parallel to each other, and the first transistor (Q2) is When a negative pulse is applied to the transmission terminal (SA) and a positive pulse is applied to the other transmission terminal (SB), the second transistor (Q4) is turned on. SA) positive pulse,
It is turned on when a negative pulse is applied to the other transmission terminal (SB), and when the second transistor (Q4) is turned on, it is energized to clearly indicate the energized state. It has a third unidirectional element (LG) and a fourth unidirectional element (LR) which energizes when the first transistor (Q2) is in the on state to clearly indicate the energized state. And

In order to correctly recognize the polarity state of the positive pulse or the negative pulse, the first transistor (Q
Between the output terminal of 2) and the fourth unidirectional element (LR), and between the output terminal of the second transistor (Q4) and the third unidirectional element (LG), Smoothing circuits (C1, R4, R5, Q1, C2, R15, R16, Q) that maintain the polarity state of the positive pulse or the negative pulse applied to the pair of transmission terminals (SA, SB) for a certain period of time.
5) may intervene.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of a LAN tester of the present invention will be described with reference to FIGS. FIG. 1 is a circuit configuration diagram showing an example of a mode in which this LAN tester is implemented, and is roughly classified into a power supply unit 2, a current detection unit 3, a forward polarity detection unit 4, and a reverse polarity detection unit 5. It is composed of a first changeover switch (changeover switch) 6 and a second changeover switch 7 having a function of a folded connection portion. In the figure, RA, R
B is a receiving terminal, and SA and SB are transmitting terminals.

The power supply unit 2 is composed of a power supply switch SWP and a built-in battery E, and the current detection unit 3 is a bipolar transistor Q3 and light emitting diodes LY1 and L that light yellow.
It is composed of Y2 and a plurality of resistors R1, R7, R8 and R14. The resistors R7 and R8 are provided to turn on the bipolar transistor Q3, turn off the bipolar transistor Q2, and supply a power supply current to the transmission terminal SA. R1 and R14 are 560
About 10 kΩ is suitable for Ω, R7, and R8. The forward polarity detector 4 includes a bipolar transistor Q4, a field effect transistor Q5, and a light emitting diode L that lights up in green.
G, resistors R12, R13, R15, R16, and a capacitor C2. The reverse polarity detector 5 includes a bipolar transistor Q2 and a field effect transistor Q.
1, a light emitting diode LR that lights up in red, and a resistor R
4, R5, R6, R9 and a capacitor C1. The resistors R10 and R11 are provided for biasing the bipolar transistors Q2 and Q4, and the capacitor C1 and the resistor R5, and the capacitor C2 and the resistor R15 form a smoothing circuit.
Resistors R6, R9, R12, R13 are 1 kΩ, R10 is 2
70Ω, R11 is 4.7kΩ, resistors R4 and R16 are 5
00kΩ, resistors R5 and R15 are 5MΩ, capacitor C
It is suitable that C1 and C2 are about 0.1 μF. As shown in FIG. 3, the first changeover switch 6 includes a switch SW1 for turning on / off the connection terminal 1a and connecting the transmission terminal SB to either the connection terminal 2a or 2b.
As shown in FIG. 10B, the second changeover switch 7 includes a transmission terminal SA, a reception terminal RA, and a transmission terminal SB.
And a receiving terminal RB for connecting the switch SW2.

Next, each test by the LAN tester of the present invention will be described. FIG. 2 is a diagram showing a connection relationship with the HUB (or AUI) 20 when conducting a continuity test by the LAN tester of the present invention, and FIG. 3 is a diagram of FIG. 1 for explaining an operation example in the continuity test. It is a circuit block diagram which extracted the principal part. That is, during the continuity test, the bipolar transistor Q3 is turned on to turn off the bipolar transistor Q2, and the monitoring of pilot data is stopped. Further, since the signal current stops flowing through the bipolar transistor Q4 as the switch SW1 (2b portion) is separated, the LAN tester 1 shown in FIG. 1 becomes equivalent to the circuit as shown in FIG.

First, in the case of conducting the continuity test of the receiving line, as shown in FIG.
As shown in, the receiving terminals RA and RB of the LAN tester 1
HUB20 is connected to and the power switch SWP is turned on. When the switch SW1 is pressed in this state and the reception line or the HUB 20 is normal, as shown in FIG. 3, the power supply current passes between the reception terminals RA and RB, and the light emitting diode LY1 → diode D1 → resistor R1 → switch SW1
Since the current flows in the path of (1a portion) → ground GND, the light emitting diode LY1 lights up in yellow, and the outside is informed that the reception line is normal. Also, the reception line or the HUB 20
If there is a failure such as disconnection, the current path will be cut off, so the light emitting diode LY1 does not light up,
It can be seen that there is an abnormality in the reception line or HUB20.

On the other hand, when conducting the continuity test of the transmission line, FIG.
As shown in, the transmission terminals SA and SB of the LAN tester 1
HUB20 is connected to and the power switch SWP is turned on. In this state, when the switch SW1 is pressed, the base current of the bipolar transistor Q3 flows from the switch SW1 (1a portion) to the ground GND via the resistor R8, so that the bipolar transistor Q3 is turned on. When the bipolar transistor Q3 turns on, the transmission line or HUB
If 20 is normal, as shown in FIG. 3, the power supply current passes between the transmission terminals SA and SB, and the switch SW1 (2a
(Part) → resistance R14 → light emitting diode LY2 → ground GND, so that the light emitting diode LY2 lights up in yellow and the outside is informed that the transmission line or the HUB 20 is normal. Further, when there is a failure such as a disconnection in the transmission line or the HUB 20, the above-mentioned current path is cut off, so the light emitting diode LY2 does not light up, and it can be seen that the transmission line or the HUB 20 has an abnormality. in this way,
The continuity test of the wiring cable is performed through a coil in the HUB or AUI without using a folding tool. That is, since the folding tool is not used, it is not necessary to follow the wiring cable as in the conventional case, and the labor required for the search work can be significantly reduced.

FIG. 4 is a diagram showing a connection relationship with the HUB 40 when a polarity test is performed by the LAN tester 1 of the present invention,
FIG. 5 is a diagram showing a connection relationship with the HUB 40 and the AUI 50 when a communication monitor is performed by the LAN tester 1 of the present invention, and FIG. 6 is a diagram for explaining an operation example in the polarity test and the communication monitor. It is a circuit block diagram which extracted the principal part of. That is, during the polarity test and communication monitoring, the bipolar transistor Q3 is off, so that the bipolar transistors Q2 and Q4 are in the active state, and the switch SW1 (2b portion) is connected to the terminal SB to monitor the pilot data. , The LAN tester 1 shown in FIG. 1 is equivalent to the circuit shown in FIG.

When the polarity test of the HUB 40 is performed, the HUB is connected to the terminals SA and SB of the LAN tester 1 as shown in FIG.
To turn on the power switch SWP. In this state, since the switch SW1 is not pushed, the base current does not flow in the bipolar transistor Q3, the bipolar transistor Q3 is turned off, and the bipolar transistor Q2 is set based on the voltage division ratio of the power supply voltage set by the resistors R10 and R11. And, a slight bias is applied to the bipolar transistor Q4. In this state, the pulse signal as shown in FIG.
When a positive pulse is continuously applied to A and a negative pulse is continuously applied to the terminal SB, the bipolar transistor Q responds to the pulse application.
4 causes the base current to flow intermittently, whereby the bipolar transistor Q4 is intermittently turned on.

When the bipolar transistor Q4 is turned on intermittently, an intermittent pulsed voltage is applied to the field effect transistor Q5 via the resistor R16. This pulsed voltage is applied to the resistors R15 and R15. Since it is smoothed by the time constant circuit composed of the capacitor C2, the field effect transistor Q5 is turned on and the light emitting diode LG is lit in green to inform the outside that it is connected with the correct polarity (forward polarity). To be done.

On the other hand, when a negative pulse is continuously applied to the terminal SA and a positive pulse is continuously applied to the terminal SB, a base current intermittently flows in the bipolar transistor Q2 in response to the pulse application, whereby the bipolar transistor Q2 is made to flow. , Will be turned on intermittently. Bipolar transistor Q
When 2 is turned on intermittently, an intermittent pulsed voltage is applied to the field effect transistor Q1 via the resistor R4. This pulsed voltage is composed of the resistor R5 and the capacitor C1. Since it is smoothed by the time constant circuit, the field effect transistor Q1 is turned on and the light emitting diode LR is turned on in red, thereby notifying the outside that the connection is made with the wrong polarity (reverse polarity). In this way, by lighting the light emitting diode LG or the light emitting diode LR, it is possible to easily confirm the presence or absence of a signal and the polarity.

Further, when performing communication monitoring, L of the present invention is used.
When the AN tester 1 is inserted between the communication cables and the HUB 40 and the AUI 50 are connected as shown in FIG. 5, when a communication waveform as shown in FIG. 8 is applied, communication is performed by the operation during the polarity test described above. The condition can be monitored. That is, when a waveform in which a positive pulse is continuously applied to the terminal SA and a negative pulse is continuously applied to the terminal SB, the light emitting diode LG lights up in green and the terminal SA
When a waveform in which a negative pulse is continuously applied to the terminal SB and a positive pulse is continuously applied to the terminal SB, the light emitting diode LR
Lights up in red, the signal can be easily monitored by blinking each of the light emitting diodes LG and LR.
Since the signal voltage flowing through the cable for turning on the transistors Q1 and Q5 is a very short pulse as shown in FIG. 7, the light emitting diode L is based on this pulse.
It is difficult to recognize with the naked eye even if G and LR are driven and turned on. For this reason, the capacitors C1 and C2 make the lighting time wide so that the lighting state can be easily seen. As described above, the polarity can be easily determined by blinking the two light emitting diodes LG and LR by detecting the direction of the signal pulse.

Next, description will be given of a case where a test for confirming the connection direction of the wiring is performed using the LAN tester of the present invention. FIG. 9 is a diagram showing a configuration example in the case of performing a confirmation test for the presence or absence of miswiring of a general-purpose 8-pin modular jack used for LAN wiring, for example. As shown in FIG. 9, the LAN tester includes, for example, a plurality of reverse connection confirmation circuits 12a, 12b, which are conductively connected to corresponding receiving terminals of a modular jack.
・ ・ Is provided. Each reverse connection confirmation circuit 12a, 12b
Is a diode D11 (D12) and a light emitting diode LD.
1a (LD2a) is reversely connected.

The modular jack (M
J) No. 1 and No. 2 of 10 are connected to one ends of pair signal lines 11a and 11b, and one signal line of the pair signal line, for example, the signal line 11a connected to No. 1 pin of MJ10. Is adapted to be supplied with a current based on the DC voltage Ea from the power supply unit 2 described above. Further, a light emitting diode LD1b which is turned on when energized is inserted and connected between the signal line 11b connected to the pin 2 of the MJ10 and the ground line. The above-mentioned reverse connection confirmation circuit 12a is connected to the other ends of these signal lines 11a and 11b.

As shown in the figure, the pair signal lines 11c and 11d are also connected to the MJ10 at its third and sixth pins. Therefore, as in the case of the pair signal lines 11a and 11b, a current based on the direct current Eb is supplied to the third pin, and the light emitting diode LD2b is provided between the sixth pin and the ground line.
And the reverse connection confirmation circuit 12b is connected to the other ends of the pair signal lines 11c and 11d.

During the test, DC voltage Ea, E
The current based on b is separately supplied from the power supply unit 2 at different timings. Since a known technique can be used for switching the power supply timing, it is not shown here. Further, the light emitting diodes LD1b and LD2b can use the circuit of the current detection unit 3 as it is.

Next, a specific example of the connection direction confirmation test by the LAN tester having the above configuration will be described with reference to FIGS. 10 and 11. FIG. 10A is a diagram showing a state in which the wiring of the MJ 10 is normal, that is, the pair signal lines 11a and 11b are connected in the forward direction. In this case, M
The current supplied from the No. 1 pin of J10 reaches the No. 2 pin of MJ10 through the diode D11 of the reverse connection confirmation circuit 12a, so that the light emitting diode LD1b is turned on.
This makes it possible to visually confirm that the wiring of the MJ10 is normal.

FIG. 10B is a diagram showing a state where the wiring of the MJ 10 is abnormal, that is, the pair signal lines 11a and 11b are reversely connected. In this case, MJ10
The current supplied to the No. 1 pin reaches the reverse connection confirmation circuit 12a from the other signal line 11b, so that the light emitting diode LD1a is turned on. In addition, the light emitting diode LD1
The current that has passed through a reaches the pin 6 of the MJ10, so that the light emitting diode LD1b also lights up. Therefore,
In this case, it can be visually confirmed that the pin 1 and the pin 2 of the MJ10 are connected in reverse.

Further, the presence / absence of miswiring between other signal lines in the MJ 10 can also be visually confirmed by this LAN tester. For example, FIG. 11 (a), when a current is supplied to the pin 3 of MJ10, during normal wiring emitting diode L
Where D2b should light up, another light emitting diode LD1
a, LD1b is lit. This state means that the wirings in the MJ 10 are sequentially shifted upward as shown in the figure, so that it can be visually recognized that the wirings are erroneous. In addition, as shown in FIG. 11B, when a current is passed through the pin 1 of the MJ10, the light emitting diodes LD2a and LD2b that should not be lit are also lit.
This means that the wiring of MJ10 is not normal. In this way, the power supply timing to the MJ10 and the light emitting diode L
The combination test with the lighting patterns of D1a, LD1b, LD2a, and LD2b makes it possible to easily carry out a confirmation test of the connection direction of the MJ10.

Although the present invention has been described with reference to a plurality of embodiments, it goes without saying that the present invention is not limited to the above embodiments. For example, the current detector 3,
Alternatively, the reverse connection confirmation circuits 12a and 12b are configured to detect the energized state by using light emitting diodes, but other than that, the current value of the flowing current is displayed by a meter or the sound (tone or volume) is used. It may be configured to notify the outside.

[0028]

As is apparent from the above description, according to the present invention, it is possible to judge whether or not there is a failure such as a disconnection in the signal line depending on the presence or absence of current detection by the current detector. Whether the signal line has the correct polarity or the opposite polarity can be confirmed by the presence / absence of pulse detection by the polarity detection unit and the reverse polarity detection unit. Further, a pseudo signal can be generated by returning the pulse of the transmission signal line to the reception signal line, and the operating state of the connected HUB or AUI can be confirmed. Further, it is possible to easily confirm erroneous connection of wiring.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of a LAN tester according to the present invention.

FIG. 2 is a diagram showing a connection relationship between HUB and AUI when conducting a continuity test by the LAN tester of the present invention.

FIG. 3 is a main part extraction diagram of FIG. 1 for explaining an operation example in a continuity test by the LAN tester of the present invention.

FIG. 4 is a diagram showing a connection relationship with a HUB when a polarity test is performed by the LAN tester of the present invention.

FIG. 5 is a diagram showing a connection relationship with HUB and AUI when a communication monitor is performed by the LAN tester of the present invention.

FIG. 6 is a principal part extraction diagram of FIG. 1 for explaining an example of a polarity test by the LAN tester of the present invention and an operation example in a communication monitor.

7 is a diagram showing a waveform example of a trigger pulse (carrier component) in FIG.

8 is a diagram showing an example of waveforms during communication in FIG.

FIG. 9 is a diagram showing an example of a configuration in a case where a general-purpose 8-pin modular jack used for LAN wiring is tested for the presence or absence of miswiring.

10A is a diagram showing a state where the pair signal lines are connected in the forward direction, and FIG. 10B is a diagram showing a state where the pair signal lines are reversely connected.

11A and 11B are diagrams showing a state in which other signal lines are erroneously connected.

[Explanation of symbols]

1 LAN tester 2 power supply 3 Current detector 4 Forward polarity detector 5 Reverse polarity detector 6 First changeover switch (changeover switch) 7 Second selector switch (fold-back connection) 10 modular jack (MJ) 11, 11a to 11d signal line 12a, 12b Reverse connection confirmation circuit 20,40 HUB 50 AUI

Claims (2)

(57) [Claims] 1. A power supply unit for supplying direct-current power at different timings for each pair signal line unit in a modular jack to which a plurality of pair signal lines are connected, and a pair of first and second unidirectional elements in antiparallel. It consists of connecting,
The end of each of the paired signal wires in the modular jack.
A reverse connection confirmation circuit connected to the end in association with the pair signal line, and one end of the modular jack located on the ground line side.
Connected between the child and the ground wire,
Comprising a third unidirectional element demonstrates a state, all of the 3 corresponding to respective paired signal lines by the DC power wiring of all paired signal lines is supplied from the power supply unit in the case of normal The unidirectional element clearly indicates its energized state, and if the wiring of at least one pair signal line has an error in polarity connection, the pair signal line having an error in polarity connection due to the DC power supplied from the power supply unit The one connected to
One of the first and second unidirectional elements of the pair
Clearly indicates the energized state, and if there is miswiring with some signal lines of other pair signal lines, they are supplied at different timings depending on the power supply unit .
The pair of first and second unidirectionality due to the generated DC power.
One of the elements, the unidirectional element, indicates its energized state
At the same time, the third unidirectional element determines its energized state.
Shows, first of the pair, one unidirectional of the second unidirectional element
Timing of the energization state manifestation by the conductive element and the third
Based on the timing when the energized state is clearly indicated by the unidirectional element,
The wiring error of the plurality of paired signal lines is detected.
LAN tester characterized by being configured as described above . 2. Both of the pair of first and second unidirectional elements
The person clearly indicates the energized state according to claim 1.
LAN tester on board.