GB2467425A - A media converter for Ethernet-to-optical conversion, for use with POF, which has fibre testing means - Google Patents
A media converter for Ethernet-to-optical conversion, for use with POF, which has fibre testing means Download PDFInfo
- Publication number
- GB2467425A GB2467425A GB1001298A GB201001298A GB2467425A GB 2467425 A GB2467425 A GB 2467425A GB 1001298 A GB1001298 A GB 1001298A GB 201001298 A GB201001298 A GB 201001298A GB 2467425 A GB2467425 A GB 2467425A
- Authority
- GB
- United Kingdom
- Prior art keywords
- media converter
- test signal
- media
- operable
- signals
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
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Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/07—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems
- H04B10/075—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using an in-service signal
- H04B10/077—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using an in-service signal using a supervisory or additional signal
- H04B10/0779—Monitoring line transmitter or line receiver equipment
Abstract
A media converter 310 is operable to convert Ethernet signals to optical signals for transmission, and to receive optical signals and convert such them to Ethernet signals. The media converter produces optical signals suitable for use with plastic over fibre (POF) 304. Preferably a first media converter 310 is connected to a second media converter 302 by a plastic fibre for bidirectional communication. The first media converter transmits a test signal 312 to the second media converter 302 and in response the second media converter transmits a second test signal 314 to the first media converter. Upon receipt of the second test signal 314 at the first media converter, the first media converter provides an indication that the POF is suitable for transmission of optical signals.
Description
Title: Media Converter
Field of the Invention
This invention relates to a media converter operable to convert Ethernet signals to optical signals suitable for transmission by a plastic optical fibre, and to convert such optical signals to Ethernet signals.
Background to the Invention
Media converter devices for use with plastic optical fibre (POF) cable have been io available to purchase on the market for some time. They are sold as standalone devices for use in bespoke installations and also in kit form with a suitable length of twin core POF cable for self install by end users.
The purpose of the media converter is to re-route conventional Ethernet signals over a is length of POF cable, typically up to 50m long.
One issue with installing POF cable is that the fibre is susceptible to light leakage, particularly where the cable has to be bent to overcome obstacles such as door frames, stairs, walls etc between the two items of connected equipment. At each bend in the cable a percentage of the transmitted light will escape from the cable.
If a length of POF cable is installed over say 30m there will be several points at which the cable is bent in order to provide a neat installation. Consequently the amount of light reaching the far end of the cable can be greatly reduced. In extreme cases, where a long length of POF cable is installed with several bends, there may be insufficient light passing through the POF cable for the attached media converters to operate correctly. Similarly it may be the case that just enough light is transmitted to enable the attached media converters to communicate, but that this amount of light is not enough to guarantee a fully reliable connection, for example because the amount of light transmitted by the POF cable will decrease as the POF cable degrades over time.
When installing existing POF equipment as described it is only practically possible to check the integrity of the optical link by connecting an Ethernet equipped device to each media converter and checking to see that an Ethernet link is established. It is not currently possible in a self install situation to determine the quality or reliability of the optical link over the POF cable.
s Summary of the Invention
According to the invention there is provided a media converter operable to convert Ethernet signals to optical signals suitable for transmission by a plastic optical fibre, and to convert such optical signals to Ethernet signals, wherein the media converter includes a test circuit operable, when connected to another media converter by a io plastic optical fibre, to transmit a test signal to the other media converter and, in response to reception of a test signal from the other media converter, to provide an indication that the plastic optical fibre is suitable for transmission of optical signals.
The invention can provide a media converter that can provide an indication that a is plastic optical fibre connecting the media converter to another media converter is suitable for transmission of optical signals. This enables a user to check the integrity of the optical link without the need to connect an Ethernet equipped device to each media converter.
The test circuit may advantageously be operable, when connected to another media converter by a plastic optical fibre, to transmit a test signal to the other media converter in response to reception of a test signal from the other media converter.
Where the test circuit is so operable, first and second media converters according to the invention connected by a plastic optical fibre may be arranged to monitor automatically whether the plastic optical fibre is suitable for transmission of optical signals, by each periodically transmitting a test signal to the other media converter and, in response to reception of a test signal within a predetermined time, typically less than 1 second, from the other media converter (which will occur only if the plastic optical fibre is suitable for transmission of optical signals between the first and second media converters) providing the indication that the plastic optical fibre is suitable for transmission of optical signals.
Alternatively or additionally, the test circuit may advantageously be operable by a user of the media converter to transmit the test signal to the other media converter and, in response to reception of the test signal from the other media converter, to provide the indication that the plastic optical fibre is suitable for transmission of s optical signals.
Where the test circuit is operable in response to reception of the test signal from the other media converter only to provide the indication that the plastic optical fibre is suitable for transmission of optical signals, a user of the media converter must cause io both media converters, for example by pressing a switch on each media converter, to transmit the test signal, which requires the user to have access to both media converters.
Preferably, therefore, the test circuit is operable by a user of the media converter to is transmit the test signal to the other media converter and is also operable, in response to reception of the test signal from the other media converter, to transmit the test signal to the other media converter.
Where the test circuit is operable in response to reception of the test signal from the other media converter to transmit the test signal to the other media converter, a user of the media converter can, for example by pressing a switch on the media converter, cause both media converters to transmit the test signal, without requiring access to both media converters.
Thus a user of the media converter would cause a first media converter, for example by pressing a switch on the first media converter, to transmit a first test signal to a second media converter. This would establish the first media converter as a master and the second media converter as a slave.
Assuming that a first core of the plastic optical fibre is suitable for transmission of optical signals, the second media converter would receive the first test signal and, in response, would transmit a second test signal to the first media converter.
Assuming that a second core of the plastic optical fibre is suitable for transmission of optical signals, the first media converter would receive the second test signal and, in response, provide the indication, for example light a green LED, that the plastic optical fibre (i.e. both cores) is suitable for transmission of optical signals.
If the first core of the plastic optical fibre is not suitable for transmission of optical signals, the second media converter will not receive the first test signal and so will not transmit the second test signal. If the second core of the plastic optical fibre is not suitable for transmission of optical signals, but the first core of the plastic optical fibre io is suitable, the second media converter will receive the first test signal and, in response, will transmit the second test signal, but the first media converter will not receive the second test signal and will not provide the indication that the plastic optical fibre is suitable for transmission of optical signals.
is The media converter may advantageously further be operable to measure a time delay after transmission of the test signal to the other media converter and before reception of the test signal from the other media converter, to determine when the time delay exceeds a predetermined time delay and, in response, to provide an indication, for example light a red LED, that the plastic optical fibre is not suitable for transmission of optical signals.
Where the test circuit is operable by a user to transmit the test signal to the other media converter, it may advantageously further be operable to stop transmitting the test signal after a predetermined time interval.
Brief Description of the Drawings
The invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a schematic diagram of a pair of media converters connected by a plastic optical fibre cable to link a telephony socket and a television receiver; Figure 2 is a block diagram of a media converter in accordance with the invention; Figure 3a is a schematic diagram of a pair of media converters in accordance with the invention connected by a plastic optical fibre cable; s Figure 3b is a time line diagram of events occurring during operation of the media converters of Figure 3a; Figure 4 is a perspective view of a display panel of a handheld plastic optical fibre link tester; and Figure 5 is a perspective view of a switch of the tester of Figure 4.
Detailed Description of an Embodiment
In Figure 1 first media converter 110 is connected to second media converter 112 by a is length of twin core plastic optical fibre (POF) cable 114. The first and second media converters 110 and 112 are connected to respective power supplies 116 and 118. The first media converter 110 is connected to a modem 120 by an Ethernet patch cable 122. The modem 120 is connected to a power supply 124 and to a telephony socket 126 by a telephony patch cable 128. Second media converter 112 is connected to a Bluewin (R) TV box 130 by an Ethernet patch cable 132. The TV box 130 is connected to a power supply 134 and to a TV 136 by a SCART cable 138. The TV 136 is connected to a power supply 140.
A complete installation will normally consist of bi-directional point to point connection apparatus as shown in Figure 1.
The media converters are normally used in pairs. Each media converter comprises a high speed optical transmitter and a reciprocate optical receiver to create a data link between two pieces of connected equipment. The end equipment is connected using conventional Ethernet (10/100/l000baseT) connecting leads made of CatS/5e/6 cable or similar. With this apparatus it is possible to create a high speed data connection in full duplex over a length of twin core POF cable.
The media converter 10 of Figure 2 comprises an integrated power supply 12, an Ethernet connection terminal 14 for connection to an Ethernet cable, a POF connection terminal 16 for connection to a POF cable, a converter circuit 18 operable to convert Ethernet signals received at the terminal 14 to optical signals for transmission from the terminal 16 and to convert optical signals received at the terminal 16 to Ethernet signals for transmission from the terminal 14, and a test circuit operable by a push button switch 22.
The media converter 10 has two modes of operation; these are "Data mode" and "Test mode". The default operating mode is Data mode. In Data mode the media converter re-routes conventional Ethernet signals over a length of POF cable as described above.
Test mode can be activated by the user by means of an external push button switch 22 to operate the test circuit 20 of the media converter 10. When Test mode is active the media converter will remain in Test mode for a period of time (typically 5 minutes) before automatically reverting back to Data mode. To use the POF test feature the user must activate Test mode on both media converters.
When Test mode is engaged an attenuation (typically 3dB reduction) is inserted into the analogue signal path of the optical receiver 16 of the media converter and each media converter will transmit a test signal in the form of predetermined data to the other media converter. Each media converter will then determine whether the predetermined data is being received. If so, a green LED (not shown) will illuminate to show the user that a good link is present. If the predetermined data is not received, or if no data are received within a predetermined time, typically less than 1 second, a red LED (not shown) will illuminate to show the user that the optical signal received is too low to create a reliable connection, or absent, respectively in this case the user is required to take corrective action to improve the optical cable link.
As a further refinement of the media converter it is possible to provide a "Master/Slave Test mode" by using a single button press on one media converter rather than needing to activate the Test mode in both media converters separately.
This mode is particularly useful where one media converter may be installed in a position that is physically difficult to reach.
Figure 3a shows a pair of media converters operating in the Master/Slave Test mode.
First media converter 300 is connected to second media converter 302 by a length of twin core POF cable 304. A first core, which carries signals from the first media converter 300 to the second media converter 302, is denoted by reference numeral 306. A second core, which carries signals from the second media converter to the first media converter, is denoted by reference numeral 308. Both the first and second io media converters have push button switches for operating the test circuits (not shown) of the media converters. Only the switch of the first media converter 300 is shown in Figure 3a, in which it is denoted by reference numeral 310.
A user of the media converters activates the Master/Slave Test mode by closing the is switch 310 of the first media converter 300. The test circuit of the first media converter 300 transmits a test signal 312 in the form of predetermined data through the first core 306 of the POF cable 304 to the second media converter 302, and starts a timer (not shown).
If the predetermined data are received by the second media converter 302, the first media converter 300 is established as the master and the second media converter 302 is established as the slave, and the test circuit of the second media converter 302 transmits a test signal 314 in the form of predetermined data through the second core 308 of the POF cable 304 to the first media converter 300.
If the predetermined data are received by the first media converter before the timer reaches a time out value, the first media converter lights a green LED (not shown), which indicates that both cores 306 and 308 of the POF cable 304 are suitable for transmission of optical signals.
If, on the other hand, when the first media converter transmits the test signal 312 the second media converter receives data different from the predetermined data (indicating corruption of the test signal 312) or does not receive the test signal 312 because the first core 306 is unsuitable for transmission of optical signals, the second media converter 302 will not transmit the test signal 314 to the first media converter 300. The timer of the first media converter will reach the time out value before the first media converter receives the test signal 314 from the second media converterand will light a red LED (not shown), which indicates that at least one of the cores of the POF cable 304 is not suitable for transmission of optical signals.
Where the second media converter 302 receives the predetermined data from the first media converter 300 and transmits the test signal 314 to the first media converter 300, but the first media converter receives data different from the predetermined data or does not receive the test signal 314, because the second core 308 is unsuitable for transmission of optical signals, the timer of the first media converter will reach the time out value before the first media converter receives the predetermined data from the second media converter.
The first media converter will therefore light the red LED, again to indicate that at least one of the cores of the POF cable 304 is not suitable for transmission of optical signals.
The sequence of events described above is shown in Figure 3b, in which the horizontal axis 316 represents time. Thus the switch 310 at zero on horizontal axis 316 represents the start of the sequence when the user closes the push button switch 310. The test circuit of the first media converter 300 then transmits the test signal 312, after which, if the test signal 312 is received by the test circuit of the second media converter 302, the second media converter transmits the test signal 314.
In the described embodiment a design improvement has also been made regarding the power supply. This is usually an external power supply unit that delivers low voltage DC power to the media converter. In the described embodiment the power supply is incorporated into the media converter. This provides several powering options for the end user, including a detachable mains power cord, a detachable mains power cord with piggyback mains socket or a detachable mains plug. Any of these mains connection options can be changed depending on the country of operation and the plug type in use.
It is envisaged that instead of the integrated power supply 12, the media converter 10 could include a USB connector, for example a mini USB-B connector, for connection to a USB power supply, which may for example be a USB adaptor or a USB power s supply of a PC. Where the USB connector is a mini USB-B connector, the media converter would be connected to the USB power supply by a normal USB-A to USB-B cable.
Figure 4 shows a handheld POF link tester 410. These devices are portable, they can io be mains or battery powered and they are used in pairs.
One tester is connected at each end of the POF cable under test. Each tester comprises a transmitter and a receiver so that both fibres of a twin core POF cable can be tested simultaneously. In each tester the receivers are modified so that an attenuation is (typically 3dB reduction) is inserted into the analogue signal path of each optical receiver. Upon operation of a toggle switch 412 (shown best in Figure 5) each tester will transmit predetermined data to the other tester and each tester will determine whether valid data is being received. If valid data is received a green LED 414 will illuminate to show the user that a good link is present. If valid data is not received a red LED 416 will illuminate to show the user that the POF installation is faulty and needs attention. When both testers show a Green LED it indicates the connection is good in both directions.
By using the testers as described above they will demonstrate to the user that an acceptable optical signal path is present. Inserting a removable fixed attenuation into the analogue receiver signal path as described provides a "safety margin" over and above that which is needed for normal operation. This margin safeguards the installation against future degradation of the optical link.
As described above the POF link tester is a very useful indication tool for use by professional POF installers. However, each tester effectively comprises a modified media converter and requires a mains power supply or battery. This clearly makes it too costly to be included in a self install kit for end users and the like, a problem the present invention aims to solve by incorporating media conversion and testing into an integrated design.
Claims (7)
- Claims 1. A media converter operable to convert Ethernet signals to optical signals suitable for transmission by a plastic optical fibre, and to convert such optical s signals to Ethernet signals, wherein the media converter includes a test circuit operable, when connected to another media converter by a plastic optical fibre, to transmit a test signal to the other media converter and, in response to reception of a test signal from the other media converter, to provide an indication that the plastic optical fibre is suitable for transmission of optical io signals.
- 2. A media converter according to claim 1, wherein the test circuit is operable, when connected to another media converter by a plastic optical fibre, to transmit a test signal to the other media converter in response to reception of a test signal from the other media converter.
- 3. A media converter according to claim 1 or claim 2, wherein the test circuit is operable by a user of the media converter to transmit the test signal to the other media converter and, in response to reception of the test signal from the other media converter, to provide the indication that the plastic optical fibre is suitable for transmission of optical signals.
- 4. A media converter according to claim 3, wherein the test circuit is operable by a user of the media converter to transmit the test signal to the other media converter and is also operable, in response to reception of the test signal from the other media converter, to transmit the test signal to the other media converter.
- 5. A media converter according to claim 3 or claim 4, wherein the test circuit is further operable to stop transmitting the test signal after a predetermined time interval.
- 6. A media converter according to any preceding claim, further comprising a power supply connectable to a mains power supply to deliver low voltage DC power to the media converter.
- 7. A media converter substantially as herein described with reference to Figures 2, 3a and 3b of the accompanying drawings.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GBGB0901373.1A GB0901373D0 (en) | 2009-01-28 | 2009-01-28 | Media converter |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB201001298D0 GB201001298D0 (en) | 2010-03-10 |
| GB2467425A true GB2467425A (en) | 2010-08-04 |
| GB2467425B GB2467425B (en) | 2014-10-15 |
Family
ID=40469184
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GBGB0901373.1A Ceased GB0901373D0 (en) | 2009-01-28 | 2009-01-28 | Media converter |
| GB1001298.7A Active GB2467425B (en) | 2009-01-28 | 2010-01-27 | Media converter |
Family Applications Before (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GBGB0901373.1A Ceased GB0901373D0 (en) | 2009-01-28 | 2009-01-28 | Media converter |
Country Status (3)
| Country | Link |
|---|---|
| CH (1) | CH700271A2 (en) |
| FR (1) | FR2941800A1 (en) |
| GB (2) | GB0901373D0 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3890248A1 (en) * | 2018-03-09 | 2021-10-06 | Elbex Video Ltd. | A method and a tester for testing and verifying the conductivity of optical cable segments linked within a cascaded infrastructure of smart residences |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| BE1026413B1 (en) * | 2018-06-21 | 2020-01-30 | Phoenix Contact Gmbh & Co | media converters |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0944184A2 (en) * | 1998-03-19 | 1999-09-22 | Sony Corporation | Optical transmitter-receiver and method of checking the connection of an optical fibre to an optical transmitter-receiver |
| JP2002094542A (en) * | 2000-09-14 | 2002-03-29 | Kyushu Ando Denki Kk | Inter-lan connection system and its loopback test system |
| US20020114046A1 (en) * | 2001-02-20 | 2002-08-22 | Ookubo Ken?Apos; Iti | Signal transmission method and apparatus, and signal transmission system |
| US6480308B1 (en) * | 1998-06-10 | 2002-11-12 | Sony Corporation | Optical communication apparatus |
| US20040017965A1 (en) * | 2002-07-29 | 2004-01-29 | Hideji Abe | Subscriber line terminal device and loopback test method |
| JP2004228771A (en) * | 2003-01-21 | 2004-08-12 | Fujikura Ltd | Media converter, loop testing method, and loop test program |
-
2009
- 2009-01-28 GB GBGB0901373.1A patent/GB0901373D0/en not_active Ceased
-
2010
- 2010-01-27 CH CH00098/10A patent/CH700271A2/en not_active Application Discontinuation
- 2010-01-27 GB GB1001298.7A patent/GB2467425B/en active Active
- 2010-01-28 FR FR1050578A patent/FR2941800A1/en not_active Withdrawn
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0944184A2 (en) * | 1998-03-19 | 1999-09-22 | Sony Corporation | Optical transmitter-receiver and method of checking the connection of an optical fibre to an optical transmitter-receiver |
| US6480308B1 (en) * | 1998-06-10 | 2002-11-12 | Sony Corporation | Optical communication apparatus |
| JP2002094542A (en) * | 2000-09-14 | 2002-03-29 | Kyushu Ando Denki Kk | Inter-lan connection system and its loopback test system |
| US20020114046A1 (en) * | 2001-02-20 | 2002-08-22 | Ookubo Ken?Apos; Iti | Signal transmission method and apparatus, and signal transmission system |
| US20040017965A1 (en) * | 2002-07-29 | 2004-01-29 | Hideji Abe | Subscriber line terminal device and loopback test method |
| JP2004228771A (en) * | 2003-01-21 | 2004-08-12 | Fujikura Ltd | Media converter, loop testing method, and loop test program |
Non-Patent Citations (1)
| Title |
|---|
| DIMOTO, "Industrial 1 Port and 2 Port Media Converter", 7 Jan 2008. Downloaded from http://www.pmmfg.com/products_detail.php?cmd=dloadDoc&doc_id=315&product_id=363 on 23 Feb 2010. * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3890248A1 (en) * | 2018-03-09 | 2021-10-06 | Elbex Video Ltd. | A method and a tester for testing and verifying the conductivity of optical cable segments linked within a cascaded infrastructure of smart residences |
Also Published As
| Publication number | Publication date |
|---|---|
| GB2467425B (en) | 2014-10-15 |
| FR2941800A1 (en) | 2010-08-06 |
| GB201001298D0 (en) | 2010-03-10 |
| GB0901373D0 (en) | 2009-03-11 |
| CH700271A2 (en) | 2010-07-30 |
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