9411 - low noise margin?

Hello,
I'm using an NI-9411 in a 9171 chassis, measuring a 5V differential signal @ < 100Hz but my frequency measurement jumps around a lot when I touch the bnc connector on the device I'm measuring (hand-held tachometer).
I was surprized to read that the input threshold for the 9411 is only 300mV. I think I'm introducing noise because the tachometer isn't pulling the signal are enough below 300mV in it's off state.
I don't have many options for external signal conditioning in this application so I'm wondering if I'm issing something in the DAQmx settings.
For instance, it looks like I can't specify the input termination (single-ended vs. differential) or the input thresholds/max range etc...
Any thoughts?

Are you saying you're showing more than 300mV when the tach should be low? What measurement are you seeing?
I would suspect you could use the wiring chart to handle the single-ended.

Similar Messages

Low noise margin. Connection keeps dropping.

Hi all.
Can anyone help? I have low sound margin and my broadband keeps dropping.
Below are my stats from my router.
ADSL line statusConnection information
Line state
Connected
Connection time
0 days, 0:54:47
Downstream
12,989 Kbps
Upstream
1,057 Kbps
ADSL settings
VPI/VCI
0/38
Type
PPPoA
Modulation
ITU-T G.992.5
Latency type
Interleaved
Noise margin (Down/Up)
2.9 dB / 6.0 dB
Line attenuation (Down/Up)
32.0 dB / 18.2 dB
Output power (Down/Up)
0.0 dBm / 12.4 dBm
Loss of Framing (Local)
60
Loss of Signal (Local)
6
Loss of Power (Local)
0
FEC Errors (Down/Up)
16894701 / 4294967259
CRC Errors (Down/Up)
1869 / N/A
HEC Errors (Down/Up)
N/A / 0
Error Seconds (Local)
1
Hide Details

john46 wrote:
Hi try this link it may help
About ADSL noise margins
John, does my explanation of noise margin make sense to you?
Updated link
About ADSL noise margins
There are some useful help pages here, for BT Broadband customers only, on my personal website.
BT Broadband customers - help with broadband, WiFi, networking, e-mail and phones.

Low Noise Margin, Regular Drop Outs of Broadband?

I have noticed recently that my HH2 type B router is showing at various times a disconnect yellow LED.    This was not causing a major problem, but on reflection I think it has been happening since before Christmas.   I decided to check on the HH2 ADSL Connections and Event Log pages and keep copies of the text from 24 Feb.   Although I usually switch the HH off with the computer, I have refrained from doing so for the last week or two in case that was a possible cause.   The Event Log shows short connection times.
I appear to have a small noise margin varying between 2.5 and 3.4 dB with the download speed of ca 18.0+ Mbps.    I have carried out a Quiet Line test on our corded phone and the line is perfectly quiet to the ear.   There have been no house wiring changes.
Looking now at the Event Log it appears that the broadband disconnects in most cases are very regular every 30 mins - most odd?   Even between 01:00 and 06:00 hrs in the morning on 25 Feb my log shows 30 min drop out interval!
Have BT made some kind of alteration to the Crowthorne exchange to cause the NM to sit below the normal level and for regular resets - seems unlikely?
Back in Dec. 2012 in my thread "Re: Failure to Reset the Line to Original Rate following Cable Replacement" I was getting 15,876 kbps with a Noise margin of 6.0dB. I still have the ferrite ring on the HH PSU cable.   It seems my line is being "squeezed" and giving me 18+ Mbps with drop outs.
Should I request a Mod to reset my NM perhaps to a more reasonable value?
Rodney Fry
24 Feb
ADSL line status
Connection time           0 days, 04:28:21
Downstream                 18,628 Kbps
Upstream                      1,078 Kbps
ADSL Settings
Noise margin (Down/Up)            2.7 dB / 5.9 dB
Line attenuation (Down/Up)       27.4 dB / 11.5 dB
Output power (Down/Up)          28.5 dBm / 1.9 dBm
Loss of Framing (Local/Remote)   0 / 0
Loss of Signal (Local/Remote)   0 / 0
Loss of Power (Local/Remote)   0 / 0
FEC Errors (Down/Up)             14779 / 57780
CRC Errors (Down/Up)              84 / 1446162
HEC Errors (Down/Up)              955 / 0
Error Seconds (Local/Remote)   57 / 203172
Event Log
Feb 24 18:02:32 2015   (28031.680000) Admin login successful by 192.168.1.69 on HTTP
Feb 24 18:02:21 2015   INF 2015-02-24T18:02:21Z cwmp: cwmp_session: session completed successfully
Feb 24 18:02:21 2015   INF 2015-02-24T18:02:21Z cwmp: cwmp_session: got empty envelope
Feb 24 18:02:21 2015   INF 2015-02-24T18:02:21Z cwmp: cwmp_session: got envelope, len=0
Feb 24 18:02:21 2015   INF 2015-02-24T18:02:21Z cwmp: cwmp_session: InformResponse is completed
Feb 24 18:02:07 2015   (28006.010000) RTNL: Received ERROR reply 'No such process' for message type 0x19
Feb 24 18:01:28 2015   ERR 2015-02-24T18:01:28Z cwmp: mt_cwmp: session error: Could not resolve host
Feb 24 18:01:27 2015   (27966.110000) danube_dsl_ioctl:88: Failed ioctl 250 errno 22
Feb 24 18:01:27 2015   (27966.060000) danube_dsl_ioctl:88: Failed ioctl 270 errno 22
Feb 24 16:05:20 2015   (20999.440000) Admin login successful by 192.168.1.69 on HTTP
Feb 24 16:05:20 2015   (20999.440000) Admin login successful by 192.168.1.69 on HTTP
Feb 24 15:41:05 2015   (19544.810000) Admin login successful by 192.168.1.69 on HTTP
Feb 24 15:10:41 2015   (17720.690000) HTTP server returned error 404
Feb 24 11:37:32 2015   ( 4931.230000) RTNL: Received ERROR reply 'No such process' for message type 0x19
Feb 24 11:36:59 2015   ERR 2015-02-24T11:36:59Z cwmp: mt_cwmp: session error: Could not resolve host
Feb 24 11:36:58 2015   ( 4897.410000) danube_dsl_ioctl:88: Failed ioctl 250 errno 22
Feb 24 11:36:58 2015   ( 4897.350000) danube_dsl_ioctl:88: Failed ioctl 270 errno 22
Feb 24 11:07:49 2015   ( 3147.950000) RTNL: Received ERROR reply 'No such process' for message type 0x19
Feb 24 11:07:02 2015   ERR 2015-02-24T11:07:02Z cwmp: mt_cwmp: session error: Could not resolve host
Feb 24 11:07:01 2015   ( 3100.000000) danube_dsl_ioctl:88: Failed ioctl 250 errno 22
Feb 24 11:07:01 2015   ( 3099.950000) danube_dsl_ioctl:88: Failed ioctl 270 errno 22
Feb 24 10:17:03 2015   ( 102.550000) WGET: Error connecting to host https://pbthdm.bt.motive.com/cwmpWeb/CPEMgt (66.193.112.93:443)
Feb 24 10:16:27 2015   ( 89.240000) RTNL: Received ERROR reply 'No such process' for message type 0x19
Feb 24 10:15:49 2015   ERR 2003-01-01T00:00:29Z cwmp: mt_cwmp: session error: Could not resolve host
Feb 24 10:15:45 2015   ( 47.310000) danube_dsl_ioctl:88: Failed ioctl 250 errno 22
3 March
Connection time       0 days, 20:04:53
Downstream              17,990 Kbps
Upstream                  1,078 Kbps
Noise margin (Down/Up)   2.5 dB / 5.6 dB
Line attenuation (Down/Up)   27.4 dB / 11.5 dB
Output power (Down/Up)   27.5 dBm / 1.9 dBm
Loss of Framing (Local/Remote)   0 / 0
Loss of Signal (Local/Remote)   0 / 0
Loss of Power (Local/Remote)   0 / 0
FEC Errors (Down/Up)   5585 / 60053
CRC Errors (Down/Up)   412 / 1492079
HEC Errors (Down/Up)   16562 / 0
Error Seconds (Local/Remote)   144 / 206517
Message
Mar 3 13:57:05 2015   (617497.220000) Admin login successful by 192.168.1.69 on HTTP
Mar 3 12:58:31 2015   (613983.530000) HTTP server returned error 404
Mar 2 17:53:34 2015   (545372.890000) RTNL: Received ERROR reply 'No such process' for message type 0x19
Mar 2 17:53:01 2015   ERR 2015-03-02T17:53:01Z c
Mar 2 17:53:00 2015   (545339.080000) danube_dsl_ioctl:88: Failed ioctl 250 errno 22
Mar 2 17:53:00 2015   (545339.030000) danube_dsl_ioctl:88: Failed ioctl 270 errno 22
Mar 2 14:20:01 2015   (532560.490000) HTTP server returned error 404
Mar 2 10:52:40 2015   (520118.800000) RTNL: Received ERROR reply 'No such process' for message type 0x19
Mar 2 10:52:06 2015   ERR 2015-03-02T10:52:06Z cwmp: mt_cwmp: session error: Could not resolve host
Mar 2 10:52:04 2015   (520083.380000) danube_dsl_ioctl:88: Failed ioctl 250 errno 22
Mar 2 10:52:04 2015   (520083.330000) danube_dsl_ioctl:88: Failed ioctl 270 errno 22
Mar 2 10:24:40 2015   ERR 2015-03-02T10:24:40Z cwmp: mt_cwmp: session error: WGET TLS error
Mar 2 10:24:40 2015   (518438.730000) WGET: Error connecting to host https://pbthdm.bt.motive.com/cwmpWeb/CPEMgt (66.193.112.93:443)
Mar 2 09:06:41 2015   (513849.940000) RTNL: Received ERROR reply 'No such process' for message type 0x19
Mar 2 09:06:08 2015   ERR 2015-03-02T09:06:08Z cwmp: mt_cwmp: session error: Could not resolve host
Mar 2 09:06:07 2015   (513815.930000) danube_dsl_ioctl:88: Failed ioctl 250 errno 22
Mar 2 09:06:07 2015   (513815.880000) danube_dsl_ioctl:88: Failed ioctl 270 errno 22
Mar 2 08:36:40 2015   (512049.360000) RTNL: Received ERROR reply 'No such process' for message type 0x19
Mar 2 08:36:08 2015   ERR 2015-03-02T08:36:08Z cwmp: mt_cwmp: session error: Could not resolve host
Mar 2 08:36:06 2015   (512015.370000) danube_dsl_ioctl:88: Failed ioctl 250 errno 22
Mar 2 08:36:06 2015   (512015.320000) danube_dsl_ioctl:88: Failed ioctl 270 errno 22
Mar 2 07:06:44 2015   (506653.590000) RTNL: Received ERROR reply 'No such process' for message type 0x19
Mar 2 07:06:12 2015   ERR 2015-03-02T07:06:12Z cwmp: mt_cwmp: session error: Could not resolve host
Mar 2 07:06:11 2015   (506619.930000) danube_dsl_ioctl:88: Failed ioctl 250 errno 22
Mar 2 07:06:11 2015   (506619.870000) danube_dsl_ioctl:88: Failed ioctl 270 errno 22
Mar 2 06:36:45 2015   (504854.390000) RTNL: Received ERROR reply 'No such process' for message type 0x19
Mar 2 06:36:13 2015   ERR 2015-03-02T06:36:13Z cwmp: mt_cwmp: session error: Could not resolve host
Mar 2 06:36:12 2015   (504820.790000) danube_dsl_ioctl:88: Failed ioctl 250 errno 22
Mar 2 06:36:12 2015   (504820.730000) danube_dsl_ioctl:88: Failed ioctl 270 errno 22
Mar 2 06:06:48 2015   (503057.100000) RTNL: Received ERROR reply 'No such process' for message type 0x19
Mar 2 06:06:16 2015   ERR 2015-03-02T06:06:16Z cwmp: mt_cwmp: session error: Could not resolve host
Mar 2 06:06:14 2015   (503023.670000) danube_dsl_ioctl:88: Failed ioctl 250 errno 22
Mar 2 06:06:14 2015   (503023.610000) danube_dsl_ioctl:88: Failed ioctl 270 errno 22
Mar 2 05:36:50 2015   (501258.910000) RTNL: Received ERROR reply 'No such process' for message type 0x19
Mar 2 05:36:18 2015   ERR 2015-03-02T05:36:18Z cwmp: mt_cwmp: session error: Could not resolve host
Mar 2 05:36:16 2015   (501225.490000) danube_dsl_ioctl:88: Failed ioctl 250 errno 22
Mar 2 05:36:16 2015   (501225.440000) danube_dsl_ioctl:88: Failed ioctl 270 errno 22
Mar 2 05:06:51 2015   (499460.480000) RTNL: Received ERROR reply 'No such process' for message type 0x19
Mar 2 05:06:19 2015   ERR 2015-03-02T05:06:19Z cwmp: mt_cwmp: session error: Could not resolve host
Solved!
Go to Solution.

Thank you both for the replies.    I had wondered 'imjolly' if there could be a reason which you appear to confirm.   I have looked at the notes in the link 'John46'.   I have not noticed any problems with the HH2 or its PSU plug; the wireless link works well and my wife can now print to the HP Deskjet from her laptop.   Three of the Ethernet LAN sockets are now in use on the HH2 for a network.   One has the print server for the DeskJet and the main and standby Win 7 and Win XP machines occupy the other two.
Perhaps this home network might have some impact on the HH performance, but this should not really be so when the disconnects have also occurred in the early morning with everything switched-off, bar the router.
I shall continue to watch the behaviour and if it becomes too annoying perhaps a higher NM would be requested.    Games, videos and TV are not watched when such such interrupts could be unacceptable.
Rodney Fry

My noise margin was hard set, but it's not now.

Some of you will have seen me going on about low noise margins affecting download speeds recently, and that the way to fix it is to get BT to hard set the noise margin at 6dB to prevent the problem. I had to do this a while ago when I was first upgraded to 21CN, and it was fine for a while. Problem is it seems the issue has returned, so I guess it's no longer capped at 6dB any more. Just making this thread so that the moderators can try to deal with it directly, since it took 15 attempts to even get BT to do as I asked last time!
Solved!
Go to Solution.

Hi
I am sorry to see you are having problems with your BT Service
I suggest you contact the forum mods they should be able to get this problem sorted for you this is a link to them http://bt.custhelp.com/app/contact_email/c/4951
They normally reply by email or phone directly to you within 3 working days they will take personal ownership of your problem until resolved and will keep you informed of progress
They are a UK based BT specialist team who have a good record at getting problems solved
This is a customer to customer self help forum the only BT presence here are the forum moderators
If you want to say thanks for a helpful answer,please click on the Ratings star on the left-hand side If the reply answers your question then please mark as ’Mark as Accepted Solution’

Can anyone help? High noise margin and low sync sp...

Hi all,
just registered on the forum so this is my first post. Hopefully someone out there can help.
I transferred my broadband to BT from Sky. With Sky my sync speed was around 4000kbps and download of about 3500kbps. I had a Netgear router with Sky but for some reason every day or so my sync speed dropped to 2500kbps and download down to 1800kbps. I had to reboot the router to get the speeds back up again, very frustrating.
I got BT broadband on 20/1/2010, set everything up and also fitted an I-plate. I noticed that line attenuation was 46db, this was previously 50.5 with sky and prior to I plate. The home hub sync was at 7200kbps at the start which i was very pleased with. I know this DLM thing is active for the first 10 days or so and speedtests during this time are not exactly accurate but still I was happy. after 3 days i did a speed test and got download of 5800kbps, chuffed to bits!
But, after 2 days at that speed the sync dropped to 2176kbps, gutted. I have only rebooted the router 3 times since the service started and each time the sync goes back to 7000kbps ish but drops again a day later. The thing I dont understand is the noise margin. Its currently at 24.5db, isnt that awfully high? Why is this? when I reboot it drops to 8-9db ish but then goes up again with the speed dropping.
currently connected to test socket, no other telephone equipment connected to any extensions
Can anyone please help/advise whats going on or how to rectify it? I'm wondering if theres a line fault somewhere.
And with attenuation at 46db I would have thought the speed could well be much higher than 2200kbps.
I'll stop babbling now,
Thanks

whitesp wrote:
Thanks for your reply Somerled,
ok so something is causing noise at a particular time, i had wondered about the quality of the home wiring, there are 4 extension sockets in the property, but again i am currently only connected to the test socket.
I dont have the old netgear router unfortunately so can't follow up on the suggestion you made.
God this is gonna be a nighmare to track down, although come to think of it I do have a dimmer on quite close to where the master socket is.
Can we say for sure that there definitely IS a source of noise/interference??
Many thanks
SOMETHING is forcing a resync, and at a low speed. The only thing that would cause that is a prolonged burst of noise.This is known to BT technicians as "REIN" (Repetitive Electrical Impulsive Noise). No point trying to get BT to investigate at this stage though, as it sounds very intermittent.
The way to spot radio interference noise is to use a suitable receiver - and the most convenient is a portable medium wave transistor radio. Tune to a quiet spot at the lowest end of the scale, and turn up the volume. All you'll hear is white noise and the occasional quiet crackle. A burst of noise strong enough to affect the DSL signal will be unmistakeable - a LOUD crackling/buzzing/rasping noise. If that coincides with a resync, you've found it. You then have to figure out what electrical device caused the noise.....
Another possible source of DSL noise problems is less obvious - noise caused by a line fault. This causes an unwanted mixing of the phone and DSL signal in a way that can't be corrected by the filters. This will have much the same effect as external interference noise.
Check this : does the router resync when the phone rings, or when the phone is in use ? If it does, then we're on to something - a fault known as an "HR" (High Resistance). If that doesn't happen, then we are back to external radio interference as the cause.
I suppose the HV lines you mention might have some effect, but it's a bit of a long shot. I'd expect noise from them would be a bit more constant, and would cause problems all the time, rather than intermittently.

Low speed - very high noise margin

Hi,
I'm looking to see if someone could resolve my connection issues. About a fortnight ago my broadband connection kept cutting out until I restarted the router, then the connection appeared fine (indeed, I was able to download 18GB that day). The following day, however, the noise margin was set much higher and the IP Profile was restricted to just over 1,000kbps.
The problem got worse as my housemate kept restarting the router in a bid to get the speed back to normal (normal being about 8Mbps). As a result, for the past week the speed has been at 575kbps.
There was no crackly interference when I tried the 17070 quiet line test and the stats I've attached to the bottom of this post are with the line plugged into the test socket:
Previous to plugging in the test socket, the stats were very similar - speed of 575kbps, noise margin in the 40s, and something like 40 'FEC down' events over the past three days.
There are now no other phoneline devices connected in the house at present (there was a landline phone which had been plugged in to another room, but was removed as a potential solution to the broadband speed problems).
Is it possible that a BTCare mod might be able to reset the noise margin to something more manageable?
Thanks in advance.
Line state:
Connected
Connection time:
0 day, 00:14:20
Downstream:
575 Kbps
Upstream:
440 Kbps
VPI/VCI:
0/38
Type:
PPPoA
Modulation:
G.992.5 Annex A
Latency type:
Interleaved
Noise margin (Down/Up):
46.6 dB / 29.6 dB
Line attenuation (Down/Up):
21.5 dB / 9.9 dB
Output power (Down/Up):
0.0 dBm / 12.1 dBm
FEC Events (Down/Up):
0 / 0
CRC Events (Down/Up):
0 / 0
Loss of Framing (Local/Remote):
0 / 0
Loss of Signal (Local/Remote):
0 / 0
Loss of Power (Local/Remote):
0 / 0
Loss of Link (Remote):
0
HEC Errors (Down/Up):
0 / 0
Error Seconds (Local/Remote):
0 / 0
Solved!
Go to Solution.

Hi
As John46 has said, you have been put into a banded profile automatically by the exchange equipment as the exchange has detected a multiple loss of connections (eg resyncs) over a period of time due to disconnections between the hub and the exchange.
The system (dlm) will automatically release you from the banded profile after 3 to 5 days of a stable connection. Though your speed may take some time to recover.
This is automatically done to prevent errors and to stabilise the line.
As your on ADSL2+ your IP Profile will be 88.2% of connection speed, as your connection speed gets better and out of the banded profile your IP Profile will immediately change automatically.
It is advised to keep the homehub/router switched on constantly and connected 24/7, as any restarts/disconnections or turning off of the router/homehub will make the dlm think there is a problem with your line and will either increase your noise margin, decrease your IP Profile, decrease your sync rate or put you into a banded profile.
This is done automatically to stabilise the line.
If you are not released from the banded profile in 3/5+ days then come back here and we can look into the issue further. If needed you can get manual be released from the banded profile (if not automatically already done so) by the BT Care Team then come back here, but you will need to have a 3+day stable connection first.
Hope that helps,
Cheers
I'm no expert, so please correct me if I'm wrong

High noise margin, low speed and repeated drop out...

Hi - I have a Home Hub 3 which is always dropping the connection. Unfortunately it gets re-booted alot as this seems to be the only way to get things moving again. I have just ordered a new router/modem to ss if that will hold the connection better but have been reading these forums and see that the Line Status and Speedtest are a good place to start. My Line Status shows a noise margin of 17.7dB - could this be my problem?
ADSL Line Status
Connection Information
Line state:
Connected
Connection time:
0 days, 03:09:09
Downstream:
7.781 Mbps
Upstream:
448 Kbps
ADSL Settings
VPI/VCI:
0/38
Type:
PPPoA
Modulation:
G.992.1 Annex A
Latency type:
Fast
Noise margin (Down/Up):
4.3 dB / 22.0 dB
Line attenuation (Down/Up):
33.6 dB / 17.5 dB
Output power (Down/Up):
19.8 dBm / 11.7 dBm
FEC Events (Down/Up):
0 / 2
CRC Events (Down/Up):
3000 / 5
Loss of Framing (Local/Remote):
0 / 0
Loss of Signal (Local/Remote):
0 / 0
Loss of Power (Local/Remote):
0 / 0
HEC Events (Down/Up):
1907 / 1
Error Seconds (Local/Remote):
794 / 6
Speed Test data via BT Wholesale site
D/L speed 3.78
U/L Speed 0.23
Ping Latency 68.38
and via BT domestic speed test
D/L Speed 5.74
U/L Speed 0.20
Connection Speed 7.97
Do you think noise is my problem and any suggestions please!!
Many thanks in advance
Andrew

Ha - many thanks the quick reply but I am un-masked already as not having a clue what I am talking about! A few hours spent reading up on things before I posted was not enough! I am plugged in to the test socket - have just done the quiet line test on 17070 from a corded phone and there is no noise. A bit of history - 18 months ago we had issues with water damage to underground lines to the house and we are now on the last usable pair (?) at that time I had all extension wiring reoved and new Master socket fitted. We have been OK but not spectacular since - we struggle to have 3 computers running off the net at times and I dont beieve we are getting anywhere close to our expected speed and then recently we have experienced drop outs and really slow speed as mentioned in original post.

Why does my noise margin start off at 6.3dB then d...

Basically every time my modem is reset, the noise margin is 6.3dB and then after that, each day it drops off another 0.1-0.3 until it gets to 5.4dB why is that ? Obviously The reason I ask is, if it gets too low it will reset my modem by itself won't it? Could the modem be the reason.

this is what i mean guys, i know that one of them is 5.9 and the others 5.8 but why is there so much of a difference
non interleaved- http://gyazo.com/40d6ce989f2e6aad93e2ac53d0391fb5
interleaved- http://gyazo.com/ed752dd4dd109e63c72aea0357209b68
these are also pretty close and look at the difference
interleaved- http://gyazo.com/ee5da83220e8fc541577eee19fee26a1
non interleaved- http://gyazo.com/986ee7fafc206a50d368afbeda9150b9
the bottom two are slightly different but why such a big gap?
why when none interleaved the max is a lot lower?
if my sync speed is lower then why does my noise margin not increase rather than decrease and not rise back up?

Help with resetting DSLAM/boosting noise margin?

I hope that by posting here I may actually get some help on my issue.
Had my BT Infinity 2 installed last week after a missed appointment (contractor), and got some helpful Openreach guys in, first last Monday to install the phone line - all went well, one pair was missing somewhere but a second OR engineer managed to solve this, told me I had a clean line.
On Thursday the fibre guys turned up, bit of hassle getting the HH5 to sync over the Data Extension Cable but got there in the end - seems the phone guy had done all the work and the line was working fine, no CRC errors, not far from the cabinet, a clean line.
However, the online fibre checker originally told me (and still does) that my estimated speed is 60-79 downstream and 19-20 upstream.
I am syncing at around 58Mb/s down but only just below 12Mb/s up - the HH5 has trained at this and it had been in and out the socket a few times on the Monday and again on the Thursday (same speed whether plugged in at the master socket or at the end of the DEC, I know this cable makes no difference anyway) - the fibre guys told me I have to get in touch with my provider (BT) to perhaps have the DSLAM reset as the auto sensing equipment at the exchange might have reduced my speed having been switched on and off so many times.
I know that the checker is just an estimate but it didn't say between 10 and 20 Mb/s, it is quite clear about the estimate of 19-20Mb/s - this was a major factor in me leaving the local cable company as I was already getting 10Mb/s upstream with them anyway. In this respect I am thinking that the (just under) 12Mb/s seems quite low.
So after phoning the customer service line a couple of times and despite being told to disconnect the router from the "white box" - I assume they mean the old Openreach modem - and getting nowhere as I insisited I don't have that and only have the new HH5, I composed a precise email detailing all of the above, and what do I receive back? This pearl of wisdom from someone in "Digital Care"...
"Dear Sir,
This is in regards to your e-mail which you have sent regarding the issue you are facing with your e-mail. I tried to call you to help you regarding your issue but could not speak with you."
Oh dear, did they actually read and understand my query - I also mentioned in my email that I could be contacted on my mobile number (given in the email, and on record as my installation was being handled by a specialist team after the missed appointments) as I do not have a telephone attached to my landline at the moment, or by email.
Now I run my own small computer repair business and am a professionally trained I.T. Consultant so I am 100% certain there is no problem on my end, how on earth do I go about getting this looked at because I feel like I am going round in circles? I don't think I can face another screen reader in India telling me to unplug my "white box"....
The noise margin seems quite low, can this be boosted - I must be between 150m and 250m from the cabinet according to the fibre guys.
Here's the relevant data from this morning:
3. Firmware version:       Software version 4.7.5.1.83.8.173.1.6 (Type A) Last updated Unknown
4. Board version:              BT Hub 5A
5. VDSL uptime:                1 days, 02:37:11
6. Data rate:       11869 / 58115
7. Maximum data rate: 11807 / 57862
8. Noise margin:               6.0 / 6.1
9. Line attenuation:         0.0 / 20.9
10. Signal attenuation:   0.0 / 19.9
and just taken now:
3. Firmware version:   Software version 4.7.5.1.83.8.173.1.6 (Type A) Last updated Unknown
4. Board version:   BT Hub 5A
5. VDSL uptime:   1 days, 10:16:36
6. Data rate:   11869 / 58115
7. Maximum data rate:   11793 / 56714
8. Noise margin:   6.0 / 5.8
9. Line attenuation:   0.0 / 20.9
10. Signal attenuation:   0.0 / 19.9
Thanks in advance for any help!

Thanks for the quick reply.
Here's the info:
Featured ProductsDownstream Line Rate(Mbps)Upstream Line Rate(Mbps)Downstream Range(Mbps)Availability Date High Low High Low
FTTC Range A (Clean)
79.5
60
20
19.6
Available
FTTC Range B (Impacted)
70.9
43.8
20
13.9
Available
WBC ADSL 2+
Up to 7
4 to 12.5
Available
WBC ADSL 2+ Annex M
Up to 7
Up to 1
4 to 12.5
Available
ADSL Max
Up to 5.5
4.5 to 8
Available
WBC Fixed Rate
2
Available
Fixed Rate
2
Available
Other Offerings
Fibre Multicast
Available
Copper Multicast
Available
As you can see my upstream is lower than the "low" impacted figure, and I was told by both the phone and fibre Openreach engineers that my line is clean with no CRC errors.
I'm not a business user.

Changing my noise margin

I posted a message a few days ago about my low internet speed and how it's just got worse and worse over a few months. The person who replied to it said that someone could help me reset my noise margin if I kept the router on for 3 days to allow it to settle. Well ,its been 3 days and I'm just looking where to go next to improve my speed.
Any help on how to go forward on this 'noise margin' reset thing would be appreciated
System Up Time 3 days 18:23:41
Port
Status
TxPkts
RxPkts
Collisions
Tx B/s
Rx B/s
Up Time
WAN
pppoa
8261919
9714453
0
2463
13761
3 days 13:45:26
LAN1
Link Down
7438050
6739367
0
4618
2423
LAN2
Link Down
LAN3
Link Down
LAN4
10M/100M
3 days 18:23:41
WLAN
300M
3537095
2681265
0
10326
1170
3 days 18:23:16
ADSL Link
Downstream
Upstream
Connection Speed
3680 kbps
448 kbps
Line Attenuation
36.0 db
15.0 db
Noise Margin
14.8 db
24.0 db
System Up Time 3 days 18:23:41
Port
Status
TxPkts
RxPkts
Collisions
Tx B/s
Rx B/s
Up Time
WAN
pppoa
8261919
9714453
0
2463
13761
3 days 13:45:26
LAN1
Link Down
7438050
6739367
0
4618
2423
LAN2
Link Down
LAN3
Link Down
LAN4
10M/100M
3 days 18:23:41
WLAN
300M
3537095
2681265
0
10326
1170
3 days 18:23:16
ADSL Link
Downstream
Upstream
Connection Speed
3680 kbps
448 kbps
Line Attenuation
36.0 db
15.0 db
Noise Margin
14.8 db
24.0 db

just stay connected 24/7 mods will post a contact us link and help reset noise margin back to 6db
After completing the email NOT PM then you join a queue of other customers waiting for mod help. The mods will get back to you in 3/5 working days either by phone or email
If you like a post, or want to say thanks for a helpful answer, please click on the Ratings star on the left-hand side of the post.
If someone answers your question correctly please let other members know by clicking on ’Mark as Accepted Solution’.

Noise Margin clearifaction pls

Hiya all,
   the other day i posted regarding my infinity 2 connection about uploads speeds, that subject is now cleared and ive accepted it.
But someone was talkin about noise margin so ive been checking it regularly and because the women at tech support said to keep an eye on it over the next few days since she phoned me on wednesday.
the folliowing is what the HH5 says is this cause for concern?
3. Firmware version:
Software version 4.7.5.1.83.8.173.1.6 (Type A) Last updated Unknown
4. Board version:
BT Hub 5A
5. VDSL uptime:
2 days, 00:06:07
6. Data rate:
8615 / 73208
7. Maximum data rate:
8556 / 61787      <<<< lower than my data rate?
8. Noise margin:
5.8 / 4.3          <<<< alot lower than it was b4 being 5.8 / 6.4?
9. Line attenuation:
0.0 / 19.0
10. Signal attenuation:
0.0 / 19.0
11. Data sent/received:
787.1 MB / 2.2 GB
my downloading seems fine, sometimes it lags and then resumes like download speed spiking if that makes sense?
Solved!
Go to Solution.

3. Firmware version:
Software version 4.7.5.1.83.8.173.1.6 (Type A) Last updated Unknown
4. Board version:
BT Hub 5A
5. VDSL uptime:
2 days, 00:06:07
6. Data rate:
8615 / 73208
7. Maximum data rate:
8556 / 61787      <<<< lower than my data rate?
8. Noise margin:
5.8 / 4.3          <<<< alot lower than it was b4 being 5.8 / 6.4?
9. Line attenuation:
0.0 / 19.0
10. Signal attenuation:
0.0 / 19.0
11. Data sent/received:
787.1 MB / 2.2 GB
Hi there,
Your noise margin has dropped below the target of 6 for the downstream (If you were to reboot the router now it would sync at a lower rate to up the noise margin - or it might resync on it's own to try and stabilise the connection)

Noise margin - Infinity 2

Folks, apologies if this question's been asked already - but can noise margin be reset or lowered on an Infinity 2 connection?
With our old ADSL line, and Billion Bipac 7800n router, I know we could lower it ourselves or ask the ISP to do it. But I can't seem to telnet into the HH5 and after reading some of the previous forum postings I'm not sure BT Openreach allow this? We had a steady noise margin of 6db on our old ADSL, however I see from the stats in the HH5 that it's currently 6.5. I know it's not much, but I was wondering if it could be lowered manually and I could get optimal speeds.
Or does Infinity/VDSL work in different ways?
Cheers!

Regrettably I do not think this can be changed by the customer or BT Wholesale. If the noise margin becomes really silly (e.g. 10dB on infinity) you can try to get it reset but it requires a BT Openreach engineer with a job number for your line and persistence on his part.
I think the target should be around 5.9-6.0dB and at 6.5dB you are only slightly above this so close to maximum bandwidth. I'm guessing 6.5dB is a current rather than average figure, so it may be at some points during the day the noise on the line has increased and so your current noise margin. Also bear in mind that depending on the chipset in your modem the noise figure may be more of an estimate than an actual measurement. However the high noise margin may be due to the BRAS profile so you have my sympathy as in my opinion 'the system' limits the sync rate rather too aggressively.

HH5 Noise Margin Infinity 2

Hi
My Noise margin is rated as 6.3/9.4 and my data rate is 14774 / 51645. Max data rate is 18137 / 63062. I have been monitoring the downstream noise margin and it is consistently sitting around the 9 mark. Is this causing my downstream data rate to be significantly slower than my Max rate?
Is a high noise margin the sign of an issue on the line / fault?
Any suggestions as to how I can get my data rate closer to the max - noticed my HH5 reboots every couple of days too?
Thanks

Thanks - I have been monitoring the noise level for 3 days and it has remained around the 9 mark with occasional drops to 7 which last for about 15 mins and then jump back up to 9 again.
Details for my line below. Until a couple of months ago I was getting a steady connection of around 60Mbps and looking at the max rate being reported by the Hub it does still seem to be reporting this however what I am actually getting is now around the 50 Mbps rate
Featured ProductsDownstream Line Rate(Mbps)Upstream Line Rate(Mbps)Downstream Range(Mbps)Availability Date
High Low High Low
FTTC Range A (Clean)
64.4
45.3
18.5
11.9
Available
FTTC Range B (Impacted)
54.8
30.6
18
7.9
Available

Noise margin too high

Hi,
I have always had 7Mbps since getting broadband more than 8 years ago. This continued when I switched to bt 3 years ago. I have got a bit lazy checking the speed but have found it has dropped to 2Mbps (checked with BT speed checker and others) when I checked last week. Last year I lost broadband to a fault that was eventually traced to the exchange and fixed. I believe the noise margin was adjusted up then.
I have not changed any phone wiring, router settiings etc in the 3 years I have had bt broadband and the hh3. I don't need it a such a high figure as my broadband has always been stable. I have even moved my hh3 from an extension in the living room to being plugged into the master socket in the hall, to no avail.
Can the mods drop my noise margin to 6db ?
The connection to my hub is 8Mbps from the exchange :
Line state:
Connected
Connection time:
2 days, 05:24:55
Downstream:
7.938 Mbps
Upstream:
448 Kbps
ADSL Settings
VPI/VCI:
0/38
Type:
PPPoA
Modulation:
G.992.1 Annex A
Latency type:
Interleaved
Noise margin (Down/Up):
13.5 dB / 26.0 dB
Line attenuation (Down/Up):
14.1 dB / 6.5 dB
Output power (Down/Up):
19.9 dBm / 12.1 dBm
FEC Events (Down/Up):
204101 / 102
CRC Events (Down/Up):
192 / 36
Loss of Framing (Local/Remote):
0 / 0
Loss of Signal (Local/Remote):
0 / 0
Loss of Power (Local/Remote):
0 / 0
HEC Events (Down/Up):
5811 / 37
Error Seconds (Local/Remote):
17 / 18
Solved!
Go to Solution.

Hi jonbaker65,
Your noise margin is fine. As you are on the 20cn network and close to the exchange the high noise margin just means that if your exchange get's upgraded to the 21cn network then you have lots of margin for improvement.
As your on the 20cn network and on ADSLMax, your IP profile has decreased to 2mbps possibly due to a recently lower sync rate (which has now gone back to ~8mbps)
Normally when this happens the IP Profile should automatically increase in 3 to 5 days time with a stable connection
To confirm this, please can you run a http://speedtest.btwholesale.com speedtest and post the further diagnostic test (You will need to do the quick test first and then click the further diagnostics button)
Then post the speedtest results with the IP Profile, it should look something like this (though ofcourse better then my example below ) :
It is also advised to keep the homehub/router switched on constantly and connected 24/7, as any restarts/disconnections or turning off of the router/homehub will make the dlm (exchange equipment) think there is a problem with your line and will either increase your noise margin, decrease your IP Profile, decrease your sync rate.
This is done automatically to stabilise the line.
Sometimes the IP Profile will not automatically release in the 3 to 5 day period and will require the BT Care Team to manually reset the IP Profile for you.
The BT Care Team usually require a 3+day DSL connection up time to show that your line is stable so that the IP Profile will not just get stuck at 2mbps again in a few days time.
I'm no expert, so please correct me if I'm wrong

Line dropping and high Noise margin follwing Excha...

Hi guys.
Back again for my biannual problem solving session. So heres my story. Our internet went off last Thursday for 10 minutes or so followed by an email letting us know that our local exchange had been upgraded, then began the problems. Incidentally, inicially I wa over the moon, my speed had increased to a blistering 10.8 Mbps.
From then on, whenever we mad eor received a phone call our broadband would drop out. I made the usual call to India, mive the hub etc etc but to no avail. eventually I decided to buy and change the micro filters. This worked, great, but why did I have to do this? Why did my filters no longer work?
I had hoped that would be the end of it, still at regular intervals, the BB is dropping out and reconnecting, each time it reconnects, the HH2 is syncing at a lower speed and the Noise margin is increasing. Only slowly but it is very irritating. We have gone down from 10.8 to just over 9Mbps. Where will it end? Anyhoo, I have spoke to India again and they are looking into it.
Any ideas/comments? Here are my stats.
ADSL line status
Connection information
Line state
Connected
Connection time
0 days, 9:28:53
Downstream
10,883 Kbps
Upstream
1,112 Kbps
ADSL settings
VPI/VCI
0/38
Type
PPPoA
Modulation
ITU-T G.992.5
Latency type
Interleaved
Noise margin (Down/Up)
8.7 dB / 5.7 dB
Line attenuation (Down/Up)
35.0 dB / 18.5 dB
Output power (Down/Up)
0.0 dBm / 12.7 dBm
Loss of Framing (Local)
0
Loss of Signal (Local)
0
Loss of Power (Local)
0
FEC Errors (Down/Up)
0 / 4294967264
CRC Errors (Down/Up)
672 / N/A
HEC Errors (Down/Up)
N/A / 0
Error Seconds (Local)
360
Solved!
Go to Solution.

Just leave it alone, it will sort itself out after a few days, its best not to get the helpdesk involved, as there is nothing wrong with your connection, its just the normal period of settling in when the tline is upgraded.
Its best not to restart or disconnect it for at least 10 days, otherwise you will end up with a much slower speed.
ADSL2+ is uses more bandwidth, so its important to keep the distance from the point where your line comes in, to the home hub, as short as possible, and have a filter at the point it enters the house, so that the broadband signal does not go down the extension wiring.
The ideal solution is a filtered faceplate at the master socket, that will ensure that you get the fastest connection speed.
Like this http://forumhelp.dyndns.info/images/adslface.jpg
or this
http://forumhelp.dyndns.info/images/newnte.jpg
Some of the older microfilters are not as effective at stopping the higher frequency ADSL2+ signals from getting into your phone circuit, which is most likely why you were asked to change them.
There are some useful help pages here, for BT Broadband customers only, on my personal website.
BT Broadband customers - help with broadband, WiFi, networking, e-mail and phones.

9411 - low noise margin?

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