Wiring system test question why a fluke IV precision of the new tester DTX series certification haven't got?
Now because of the need to support testing, 10 g Ethernet standards are in discussions on the precision of the instrument need to only achieve IV precision instrument to support basic tests of 10 g Ethernet. But now, whether TIA, ISO or IEEE, wasn't on IV accuracy should be what kind of standard yet final, so now we can only do our draft instrument more than IV of the definition of accuracy, but you don't get any certification or statement.
But now the system needs to be tested on the market were more than 6 classes and five classes, 10 g application of domestic commercial case yet. 6 class integrated wiring system according to the relevant provisions of the standard tester needs to meet the accuracy level III. For precision instrument certification of international institutions currently have UL and ETL two more famous, fluke certification of cable tester integrated wiring system at the same time the precision of the two agencies certification, for clients of investment, is a very good protection.
Wiring system test question 2 Why fluke as "expensive" adapter to use
Some vendors with no adapter integrated wiring system test plan, principle is reference fiber integrated wiring system to set a reference value in the test method. In theory, does have its unique feature.
But if we from the actual situation to examine, you will find the problem. If these vendors to see the instrument specifications, they will require you to use good jumper Settings for reference. So what is a good jump line? Is in accordance with ANSI/TIA/EIA - 568 - B. And IEC61935 2-1-2 forpatchcordtesting. Standard tested, or you think it is good to jump line? And their sales personnel at the scene demonstration, using highly damaged jump line does not affect the final test the validity of the integrated wiring system. Really the case?
First of all, what's good jumper? You to buy jump line, no matter who is supplier, producer who it was, they will tell you their jump line is good, but the fact is that the ANSI/TIA/EIA - 568 - A - 4 5 kinds of jump line standard is after numerous changes, the certification before the formal finalized, because of the performance of jump line deviation is very large, different manufacturers, different batch production of jumper wire on the electrical properties have very big difference, only through certification test through the jump line can be considered to be "good" jump line. No adapter and integrated wiring system test plan when doing the reference set, using only a jumper, formal integrated wiring system test need two jumpers. Then the second jump thread on the performance of the impact of the test results, how to authenticate, how to guarantee?
You will find the live demonstration, vendors will have done for the first reference to set jumpers, and ignore the second root was not jump line for your reference. This jumper is invisible, is a loophole. Do demonstration instrument, the environment will formally integrated wiring system test environment than simple, technical personnel also like to use a good link quality, ensure that two integrated wiring system testing by the results. Such subjects, the tester and onlookers are all's well that ends well. But things tend to be more complex scene, a lot of link is not a big margin to offset the adverse impact of jump line. If this is due to invisible jump line test results do not pass, who should pay?
Simple for a parameter, for example: the characteristic impedance. Jump line allowed within 5%, the characteristic impedance of deviation and link allows the characteristic impedance of deviation within 15%. Assuming jump line characteristic impedance of 95 ohms, link the characteristic impedance of 115 ohms, two are according with the standard deviation range, but both the impedance of the deviation between each other for 20 ohms, deviation of 20%, as a signal reflection, can make the ideal test results? Due to the characteristic impedance mismatch between jump line and the link of integrated wiring system test is not passed, who should pay?
In addition, if you use a special adapter, then connect the link only a RJ45 connection, if no adapter using integrated wiring system test plan, the link will be more an extra RJ45 connection. As is known to all, RJ45 connection for the structure of the cable is damage effect, RJ45 crystal head performance is not stable, especially due to the more strict 6 class, basically can't buy on the market can be used for the user to manufacture its own jump line of crystal head. If use without adapter test scheme, in between the two crystal head due to the NEXT, RL, FEXT interference signals such as repeated impact of superposition, the if treat?
This is not a simple set of reference can solve the problem. Jump line head and crystal instrument interface and the coupling between the formal to test the link between modules of integrated wiring system coupling, can be completely different. So integrated wiring system test, if not through, that who will pay?
Sounds cheap and simple solution, but in the real world, there is no looks so beautiful. Using performance cannot be determined completely jump line, the integrated wiring system testing on site completely incapable of certification testing solution, in what is now the owner of project quality is more and more attention, it is like the blind leading the blind, a deep pool in the night, is very dangerous.
Using a special adapter, first of all, it's test jumper is SSTP integrated wiring system, the characteristic impedance of 100 ohms plus or minus 1 ohm, can be in the field calibration, in RL, NEXT, FEXT guarantee its not adverse impact on the result of the test, secondly, it USES the test module, internal without cable, is completely integrated circuit connection, avoid the influence of RJ45 crystal head NEXT, such test results are correct, fair and scientific.
Wiring system test question three hot days when integrated wiring system test, why attenuation is always not qualified?
Cable attenuation by the length of the link, the influence of factors such as temperature, humidity. For six types of cables, the standard is specified, the working temperature of cable for 20 oc, within the scope of the 20 oc to 40 oc, temperature rise per 1 oc, the attenuation increases by 0.4%, between 40 oc to 60 oc, temperature rise per 1 oc, the attenuation increases by 0.6% when in fact cable in 40 oc attenuation will be 8% higher than 20 oc. So the hot weather, long link, such as more than 80 m of the link, the attenuation test is usually a FAIL. Many engineering manufacturers hope to be able to at the time of integrated wiring system test some temperature compensation method of reducing unqualified caused by high temperature attenuation situation, improve the passing rate. In ANSI/TIA/EIA - 568 - B before officially promulgated, integrated wiring system test at the scene when there are at the scene of the test instrument input temperature, compensate by calculation.
But in practical application, the attenuation is a key parameter, its relationship to the final application will be to ensure that the strength of the signal receiver received enough when, so temperature compensation is not desirable. In the ANSI/TIA/EIA - 568 - B. 2-1 and ISO/iec11801and: after 2002 officially promulgated, the field temperature compensation is no longer an acceptable solution.
In order to ensure that the final channel attenuation performance, the only way is according to the site condition will be cut short a permanent link length accordingly. Specific can refer to the table below to calculate according to the field temperature should be how to adjust the permanent link length. The whole length of the channel, we assume that the longest when 20 oc for 90 m level link with 10 m users jump line.
If due to the construction site must be longer than 80 m of the link, you need to co-ordinate with the landlord, explains the relationship between attenuation and length, temperature, and obtain the owner's understanding, accept the attenuation through the integrated wiring system test information point. But due to the attenuation of unqualified link in data transmission is very unstable, so should try to persuade the owner, or the link as the application of low speed data transmission or phone.