Trilithic 860 tricks

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I have a few but Id need one in front of me to get it right.

How do you guys have yours set up and what do you feel is their most effective use?

I really like the Macro -
Auto Test feature.
Macro the following-

Levels/Tilt
MER/BER
Spectrum/ingress
WebTest

Get to the job, hit "Auto test" the meter performs all the above tests and gives you a detailed report of all levels, snr, ingress, xmit power etc. I think you can set up to 16 or so macros performing all different test for whatever you are there for. Latency, jitter, throughput, etc.


Remote Viewing -Level III enchantress +10agil, -3 dexterity

Each 860 has its own static IP. When you are at your job you can give that IP to your sup and he can go to any web browser anywhere, type in the IP and see EXACLTY what you see on your meter and also control it.
- This only works obvioulsy with the 860's modem active. Once you try to take regualr signal levels the 860 asks you to kill the modem first so remotely you can only do all things "WEB" like throughput and grab some MER BER's or what have you.

The website looks exactly like your 860. It basically shows your 860, just the grey body, not the black rubber and the screen. Your sup can use his mouse to press all the buttons and almost real time your screen in the field will change and do whatever tests he is setting up or he will see exactly the test results you see.




REMOTE VIEWING IMAGE BELOW

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that remote viewing piece was so enchanting I just had to try it, I hooked my meter up to an extra cable outlet in my house and put the ip adress in my ie broswer and there I was, the interface seems to be very slow or laggy, could be my computer or connection though.

Tool you seem to know alot about the 860 think you could help me with a couple things, my training on it was very minimal and the instruction manual on the cd is just to darn lengthy.

1st question when you are looking at the Cable Modem statistics page what does the corrected & uncorrected counts mean under downstream. I am assumeing it's either qam errors or codewords errors but not sure, do you know what those counts means and how I should be using that data?

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Thats your MER/BER pre and post correctables. The modem in the tri will correct errors, your HSI modem will correct errors just like the cable box does, the VOIP modems will NOT correct errors.

When I get time Ill give ya more unless someone else does.

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...your HSI modem will correct errors just like the cable box does, the VOIP modems will NOT correct errors.

Not quite accurate, Tool. While all modems will use FEC (forward error correction) to recover bit errors, the difference with VOIP is that when FEC isn't enough to fix damaged codewords, the data is lost, and call quality suffers. Regular data is retransmitted on the request of the receiving end, so only throughput is affected.

Speck...
Pre-correction errors are usually shown as a negative exponent. An error rate of 1.0E -8 means one out of 100,000,000 bits is errored. The longer the measurement is made, the better, because for valid results, the meter needs to "see" a couple of hundred million bits. The lower the "-x" number, the better (-8 is better than -7). The lower limit to acceptable BER at the modem is 1.0E -7 (9.99E -6 is just about equal to this). Post correction BER any worse than 1.0 -9 indicates some kind of problem, and data is being corrupted.
MER is similar to BER, except it's more related to the RF signal itself. It simply gives a value in dB to indicate how "clouded" or dispersed the constellation appears. The tighter the clusters in each block of the constellation, the better the MER.

There's a good read here:
http://chapters.scte.org/rockymtn/documents/DigitalTesting2.ppt
It's a powerpoint presentation by Sunrise Telecom engineer Larry Jump. He does on site training... nice guy

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...your HSI modem will correct errors just like the cable box does, the VOIP modems will NOT correct errors.

Not quite accurate, Tool. While all modems will use FEC (forward error correction) to recover bit errors, the difference with VOIP is that when FEC isn't enough to fix damaged codewords, the data is lost, and call quality suffers.

Thats what I was getting at. Techs see the error correction and think all is good. Even though on the tri it appears "corrected" the voice still suffers. I guess saying it wil not -correct it at all- is inaccurate. It will not correct the issue is more accurate.


Also when looking at your mer/ber it is a good idea to look at AFEC with pre and post.
Go into SET UP highlight and select DIGITAL. The second variable from the bottom ( I forget exactly what it is) says something like AVP HARDWARE- Change it to AVP SOFTWARE. This will give you AVERAGE error correction as opposed to real time.
Real time is good for line work and tracking an issue. Average is more usefull for service and install work.

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Thanks, Tool...

I haven't played with the Trilithic model, as we're all Acterna/Agilent/JDSU here. Sounds like a flexible unit. Hope they're providing training on using them... I know it's always been an issue. !duh

I personally cant wait to get a meter that can actually "read" a digital channel, rather than just give me a level (Calan).

RF

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This is some serious damaged code words.

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You know we had that fire drill before and it was all HAM radio. We had our upstream centered at 26 MHz and Mr HAM Radio dude got off work toyed around on his CB radio and screwed us. We have 30 MHz return which sucks so we moved frequency to 25 and HAM guy was at 27 MHz.

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Where do you find the static IP at?

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So here is an 860 Question
We have 2 FWD's for the internet coming in to 1 of our HUBs. the return is split on to 2 different cards of the UBR.
While making a six foot plant the 860 meters modem says its's getting somewhere around 2000 CORR on one FWD
and gets around 200 CORR on the other FWD after being connected for say about 5 mintues.

MER / BER check the same on both. I don't recall the exact levels.

I dont have an 860. I'm not fond of them and don't want one. However, our Demand Maintenance guys have them and are pestering the shit outta me about this. I have no idea what this really means other than it appears as a " Corrected Codeword Error". I'm assuming it's a FWD path issue. The Headend Techs is telling me that I have a noise issue, which is possible but the USSNR stays about 29-30 so not VERY likely but I'm open to suggestions.
It plainly states that its a DOWNSTREAM signal issue to me but maybe I just don't get it.


Suggestion on what to try ?

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A couple of ?'s
What kind of ubr and card are you using?
Where are you sampling the signal, relative to the ubr downstream outputs?
What is the signal path (out of ubr, into split/combiner/upconverter/laser/reciever etc.)
Are you using upconverters?
What level do you have at the source, and the sample location?
WHat's the SNR/MER/BER at the source, and at the sample point?

IMPORTANT!!
When measuring for degradation of digital, always attenuate the rf into your analyzer to be equal in power level at all testing locations.

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RESPONSE INCLUDED IN QUOTE

A couple of ?'s

What kind of ubr and card are you using?  --   CISCO / UNKNOWN

Where are you sampling the signal, relative to the ubr downstream outputs?

    --    WE ARE FIBER LOCKED, SO WE HAD TO COMBINE AN UNMODULATED IF FROM ONE CARD WITH THE MODULATED CARRIER FROM THE OTEHR CARD SO THAT ONE ARRIVES IN IF FORMAT AND IS CONVERTERED AT THE ONE OTN AND THE OTHER FWD CARRIER ARRIVES AS A MODULATED CARRIER. THE IF IS PULLED OFF WITH A DIPLEXER BEING A 45 MHZ SIGNAL AND SENT TO THE MODULATOR, THE OTHER IS PULLED OFF THE HIGH SIDE OF THE MODULATOR AND SEPERATERATED BY THE DIPLEX FILTER.  THEN BOTH SEPERATED MODULATED SIGNALS GO THROUGH A HEADEND AMP AND COMBINED THERE WITH THE COMMON LINE UP.

What is the signal path (out of ubr, into split/combiner/upconverter/laser/reciever etc.) EXPLAINED ABOVE

Are you using upconverters?  -- NO 

What level do you have at the source, and the sample location?
 I AM CREATING A 6 FT PLANT USING A 4 WAY HOOKED UP BACKWARDS, I THEN CONNECT THIS GUYS METER TO THE COMBINED FORWARD FOR 1 UBR WHICH FEEDS SOME OF THE LASERS IN THE OTN AND THE RETURN COMBINIG NETWORK FOR THAT CARD WHICH GIVES ME  A CORRECTED CODEWORD ERROR COUNT OF APPROX 200 AFTER 5 MINUTES, WHEN I USES THIS SAME CONFIGURATION FOR THE OTHER FWD FOR THE OTEHR SET OF LASERS THE CORRECTED CODEWORD ERROR COUNTS INCREASE MUCH FASTER AND REACHES ABOUT 2000 CORRECTED CODEWORDS ERRORS AFTER 5 MINUTES
LEVELS IS 8 DB ON QAM CH AND 18 DB ON THE REST OF THE ANALOG CHANNELS


WHat's the SNR/MER/BER at the source, and at the sample point?

ANAYLING THE QAM CARREIR AT 117 MHZ THE SNR/MER/BER ARE ALL AT THE SAME LEVEL AND QOS READINGS

IMPORTANT!!
When measuring for degradation of digital, always attenuate the rf into your analyzer to be equal in power level at all testing locations.

ALL THE LEVELS WERE THE SAME

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Not ignoring you, just kinda digesting the info and trying to visualize the setup.

I would say though that in the headend/hub environment, your digital streams should run at 38MER or better, and pretty much error-free. Check adjacent digitals for similar issues; if they are, then consider optical issues like laser clipping, amplifier overdrive, etc. If not, then isolate the channel at the source, check for errors, then move downstream sampling at each possible location until the errors start occuring. Also check that you dont have sweep signals interfering... check the guard-bands.

There can be so many possibilities...

You can even test the IF out of the ubr, by creating a channel at 45MHz in the meter, with the standard DOCSIS specs.

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I haven't had the opportunity to check anything beyond the FWD combining as of yet. Since I don't have the meter to test it; The guy who has the meter doesn't want to come in early to work on it and in order to work on it to diagnose it I have to shut off about 800 modems /emta's. There are no real testpoint locations to check. Otherwise ....
It doesn't seem to be causing much problems by means of service calls...so.....
But it has been eating at me a bit.
I've been off work sick the last 3 days so I haven't spent too much time thinking about it.

Didn't consider making a 45 MHz Channel. Thats a great idea!

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Where do you find the static IP at?

It does not appear to be static chappy, but there is a CM info button in modem mode [cmstat] that will give you both the CPE IP and Cm ip I believe its the CM ip you want.

It's a nifty feature but not really useful because if you try to use a cellular connected lap top to help your buddy its painfully unresponsive. The only use I could see for it is as a sup pulling up on a job you are on to see if you are using your meter or not, but then if he doe snot know where you are at in your diagnostic or your IP got changed...

Its more of a training/record how to properly do it thing IMHO.

You can also just go the the my860.com site if you want to see it its pretty much the same thing except the IP way goes to your meter.

That said in our FFO there is an issue with the meters. If you lock in as a modem [cm stat/modem macro/whatever] the downstream signal drops by 3-4 db from you a straight level reading.

BTW has anyone figured out all the tricks on the advanced spectrum analysis feature yet. Still trying to figure out how to turn off the signal carriers and view the noise levels below.