Cable Tester - Odd with 1-GB Devices

[mhoppes]

So my understanding is with GBit devices you can run the cable test with them powered on. But, I have a Rocket AC connected to a cable to a Netonix.

With the AC powered on and at 1-GB I get "Abnormal Termination" on all pairs and a length of 59 feet. With the Rocket powered off I get cable lengths of 259feet (about right) and OK on all pairs.

What does this indicate???

[sirhc]

I am not sure, can you play around and give more feedback?

Suggestion for controlled test/lab:
Use your 8 port in your office
Make a 50' cable
Plug cable into rocket AC in office
Run cable tests with it on and off

[mhoppes]

Control shows the same on or off. But then this does me little good if the cable tests good until I put power on it :)

Note I'm not saying this is a Netonix issue. But the test is worthless in this case, whatever is wrong, as the issue doesn't show up until the radio comes online.

[sirhc]

With the AC powered on and at 1-GB I get "Abnormal Termination" on all pairs and a length of 59 feet.
With the Rocket powered off I get cable lengths of 259 feet (about right) and OK on all pairs.

You are supposed to do a cable test prior to powering up a POE port on a new cable run and from what you say the cable test is working properly until you apply power?

So no the cable test is not worthless it tells you before you apply power that the cable run is OK and there are no cross shorts and the cable lengths are equal which means the cable is OK.

Once you apply power the result is messed up?

So I would not call this worthless as you were able to determine the following:
1) The cable did not have any dead shorts.
2) The cable pairs all report the same length which tells you the cable is not damaged from being stretched or kinked during installation.
3) All the ends are properly terminated.

So now you know you can apply power SAFELY and that the cable at least appears good (Remember these tests are not the same as an expensive cable tester the cable)

So I am at a loss as to how it is useless????

The fact that after power is applied to the Rocket AC and the tests become whacked indicated that maybe the Rocket AC is doing something that the switch test does not like so I will have to send on to the Engineer to tear apart and see what UBNT is doing with the Rocket AC that it does not like. Maybe they are tagging digital negative to ESD ground wire supplied Earth Ground again?

The cable test works perfectly with airFIBER Radios and we both know the Chicago team does things right! For what I saw they (Chicago) does NOT tag Digital Negative to ESD ground wire supplied Earth ground and they isolate the proper circuits as they are supposed to.

[mhoppes]

Ok. Fair enough. The odd thing is the cable length goes to 59feet on all four pairs when I apply power.

[sirhc]

Ok. Fair enough. The odd thing is the cable length goes to 59feet on all four pairs when I apply power.

Agreed!