Difference between noise margin and noisy line

Hi
This issue has always bugged me. Am transferring to BT Infinity next week from Sky and have mixed feelings. We live a fair way from the exchange so line attenuation is a problem but we mange to get 3.5-4Mb with absolutely zero outage using the Sky unlimited package. Our current router stats are posted below and I woud be grateful for your interpration of the noise margin figs. Is the 7db download commensurate with a quite and stable connection that bodes well for Infinity? I'm curious cos our phone line is noisy with much background niose despite the fact that we don't have any fancy gadgets and use filters just about everywhere.
I'd just like your views on noise on the line versus noise margin for broadband and how each might impact on Infinity when we're connected next week.
Many thanks for your time.
Router StatisticsSystem Up Time: 05:44:16
Port Status TxPkts RxPkts Collisions Tx B/s Rx B/s Up Time
WANPPPoA
403055
369851
0
14261
13203
05:42:39
LAN100M/Full
370239
415781
0
13527
14890
05:44:11
WLAN11M/54M
8864
0
0
150
0
05:43:58
ADSL Link Downstream Upstream
Connection Speed4093 kbps
796 kbps
Line Attenuation51 db
28 db
Noise Margin4 db
14 db

Enter your attenuation here http://www.kitz.co.uk/adsl/max_speed_calc.php
Results are approximate
If any post helps tick the star box on the left
Just cause Im paranoid dont mean they are not out to get me

Similar Messages

Question about Noise Margin and Line Attenuation a...

1.       For several years I have had a BT telephone line. From the utilities provided by http://www.kitz.co.uk/adsl I find that I am connected to the Exchange at Merton Park (BT Code: LSMEPK) Distance:-   Direct:   960 metres (appx)* By Road: 1.29 km. Exchange Status ADSL enabled: March 30, 2000 DSL Max enabled:   March 30, 2006 SDSL enabled : Enabled 21CN due : (PSTN) N/A 21CN WBC (Broadband)   Enabled 15.02.09
2.       I previously had broadband from UKOnline and used a Speedtouch 570 adsl modem. I was paying £9.99 for a speed of 1MBit/s – in practice 700K – which was fine for most purposes but BBC iplayer did struggle a bit. UkOnline has been taken over by SKY so I switched to BT Total Broadband Option 3 in mid December, and initially used the Speedtouch 570 as there were delivery delays on BT Home Hub 2.0 due to weather conditions. Speed was initially very good but did not measure it.
3.       After Xmas I set up the BT Home Hub and ran a speed test - the profile was 2.5MBit/s. I was disappointed to get less than 3Mbit/s which is needed for BBC iplayer HD.
ADSL line status
Connection information
Line state Connected
Connection time 0 days, 2:26:57 ------> 6th January 2011
Downstream 2,268 Kbps
Upstream 440 Kbps
ADSL settings
VPI/VCI 0/38
Type PPPoA
Modulation ITU-T G.992.5 ---à this apparently means ADSL2+
Latency type Interleaved
Noise margin (Down/Up) 15.7 dB / 31.9 dB
Line attenuation (Down/Up) 27.0 dB / 9.7 dB
Output power (Down/Up) 0.0 dBm / 12.7 dBm
Loss of Framing (Local) 22
Loss of Signal (Local) 3
Loss of Power (Local) 0
FEC Errors (Down/Up) 6512 / 0
CRC Errors (Down/Up) 0 / 2147480000
HEC Errors (Down/Up) nil / 0
Error Seconds (Local) 2
4.       As part of the “slow speed wizard” I looked into getting the accelerator plate for my NTE5 split face master socket available for postage only (£1.20) but the web form advised me that if I proceeded with this order the broadband contract would automatically be extended by 12 months. I checked my BT internet account and was surprised to find an email (23rd Dec 2010) advising me that as an Option *1* customer I was in danger of exceeding my usage allowance – which surprised me as I am definitely Option 3. I wondered if I had had the speed throttled. Therefore phoned BT accounts who said the email was a mistake - I am Option 3, also said that accelerator plate was unlikely to make a difference.
5.       I contacted the BT call centre who talked me through various options. Plugging the hub direct into the master socket made no difference. They also ran a line test and said the line was fine.
6.       I therefore browsed the community care forum and find that disappointing speeds are not uncommon. One of the threads mentioned disconnecting the bell wire on the extensions. I follow this advice and removed line 3 on all extensions and then checked the ADSL status on the hub.
ADSL line status
Connection information
Line state Connected
Connection time 0 days, 6:33:45 10th January 2011
Downstream 2,272 Kbps
Upstream 888 Kbps
ADSL settings
VPI/VCI 0/38
Type PPPoA
Modulation ITU-T G.992.5
Latency type Interleaved
Noise margin (Down/Up) 31.8 dB / 14.4 dB
Line attenuation (Down/Up) 27.0 dB / 9.7 dB
Output power (Down/Up) 0.0 dBm / 12.3 dBm
Loss of Framing (Local) 0
Loss of Signal (Local) 0
Loss of Power (Local) 0
FEC Errors (Down/Up) 0 / 0
CRC Errors (Down/Up) 0 / 2147480000
HEC Errors (Down/Up) nil / 0
Error Seconds (Local) 0
7.       This had a dramatic improvement on Upstream speed – and a big change to the noise margin Noise margin which had been (Down/Up) 15.7 dB / 31.9 dB and is now Noise margin (Down/Up) 31.8 dB / 14.4 dB. It did not improve the download speed.
8.       In the following days the BT hub has not been particularly stable with some intermittent loss of wireless connectivity every few hours. Examining the event log I was a bit disconcerted to see alterations to firewall settings had happened (which I hadn’t made) and resets which I am pretty certain I hadn’t made – and a userid login with a name like TR69. Perhaps these are occasioned by the BT speedtester? To be fair I had reset and powered off the hub a number of times in attempt to sort out this problems.
9.       I have switched to a Netgear DG83GT (V1.03.23) for the time being until I have what I can regard as a reasonably fast stabile connection. At the time of writing this has been stable for 20 hours DownStream Connection Speed 2268 kbps UpStream Connection Speed 888 kbps.As stated earlier I would like downstream to be faster.
The perceived wisdom on the forum seems to be that several days of complete stability are required if there is to be any improvement on speed.
10.   If a moderator or anyone with the relevant experience reads this I would be very grateful for answers to the follow questions:
A.      Is the change in the Noise Margin parameter a good thing or a bad thing?
B.      Are the line attenuation figures acceptable for a distance of under 1.5kilometres to the exchange?
C.      Should I be able in theory to get a faster speed i.e. downstream 3Mbit/s?
D.      From the forum it seems to take several days for speed adjustments to be effected or to take effect – is this a technical issue or a policy issue?
Many thanks.
Robert
Solved!
Go to Solution.

Good Morning - it is now 6 days since this posting. During this time there have been 2 resets of the adsl line
Fri, 2011-01-14 03:28:43 - LCP down.
Fri, 2011-01-14 03:28:54 - Initialize LCP.
Fri, 2011-01-14 03:28:54 - LCP is allowed to come up.
Fri, 2011-01-14 03:28:54 - CHAP authentication success
and
Sun, 2011-01-16 16:37:26 - LCP down.
Sun, 2011-01-16 16:37:36 - Initialize LCP.
Sun, 2011-01-16 16:37:36 - LCP is allowed to come up.
Sun, 2011-01-16 16:37:36 - CHAP authentication success
These were not initiated by me - and since noise margins and sync speeds changed as a consequence can I assume that this is evidence of the adaptive process working?
Secondly, as you can see, the noise ratio has vastly improved as have the upstream and downstream sync speeds
        System Up Time 157:54:52
      ADSL Link          Downstream          Upstream
      Connection Speed           11199 kbps           1091 kbps
      Line Attenuation           27.0 db           9.9 db
      Noise Margin           14.8 db           9.2 db
BUT from the BT speedtester, as shown below I seem to be stuck in a banded IP profile of 1750/1091 which is very different from the downstream sync speeds of 11199 Kbps(DOWN-STREAM)
Can BT staff take action to alter this? If they can how do I contact them?
Regards,
Robert
18th Jan 2010
Download Speed    1288 Kbps
0 Kbps   2000 Kbps
Max Achievable Speed
Download speedachieved during the test was - 1288 Kbps
For your connection, the acceptable range of speedsis 800-2000 Kbps.
Additional Information:
Your DSL Connection Rate :11199 Kbps(DOWN-STREAM), 1091 Kbps(UP-STREAM)
IP Profile for your line is - 1750 Kbps
The throughput of Best Efforts (BE) classes achieved during the test is - 2.28:10.77:87.0 (SBE:NBEBE)
These figures represent the ratio while sententiously passing Sub BE, Normal BE and Priority BE marked traffic.
The results of this test will vary depending on the way your ISP has decided to use these traffic classes.
2. Upstream Test: -provides background information.
Upload Speed       896 Kbps
0 Kbps   1091 Kbps
Max Achievable Speed
>Upload speed achieved during the test was - 896 Kbps
Additional Information:
Upstream Rate IP profile on your line is - 1091 Kbps

Difference between Transaction Figures and Line Items

Hi,
I gone through FI like FI-GL,FI-AR,FI-AP..there i find...
Line Items & Transaction figures as main...like
in FI we have
Line Items - 0FI_GL_4,0FI_AR_4,0FI_AP_4 etc...
Transaction Figures - 0FI_GL_6,0FI_AR_6,0FI_AP_6 etc...
Now Can some please explain...
what exactly Line Items are?
What exactly Transaction Figures are?
How data flows from end to end in FI? i.e where exactly GL,AR,AP comes into picture..how they are internally related?
Some one please explain me in detail (with expamles if possible) and quick reply is much appreciated...
Regards
Ramsunder

Hi
What exactly line items :
Line items are document items that were posted to a specific account. In contrast to a document item a line item only contains the information from the document that is relevant from the account view.
You can display the following line items:
Open items, Cleared items, Noted items, Parked items ,Items with special G/L transactions (in Accounts Receivable and Accounts Payable),Items with customer or vendor items (in Accounts Receivable and Accounts Payable)
You can display the line items for the following account types: Customer accounts,Vendor accounts,G/L accounts.
What exactly Transaction Figures are?
Transaction figures are the sums of line items on the debit or credit side. The balance is the difference between the debit and the credit transaction figure.
If you take General ledger
AP records all accounting transactions for dealings with suppliers(Vendors). Much of its data is obtained from procurement (Materials Management).
AR records all accounting transactions for dealings with customers. Much of its data is obtained from Sales and Distribution.
Asset Accounting records all accounting transactions relating to the management of assets.
Travel Management manages and calculates travel costs and supports travel planning and travel expenses.
Bank ledger supports the posting of cash flows.
Regards
Chandra Sekhar T

Differences between High cardinality and line item dimension

Please Search the forum
Friends,
can any one tell me the differences between High Cardinality and Line item Dimension and their use.
Thanks in Advance.
Jose
Edited by: Pravender on May 13, 2010 5:34 PM

please search in SDN

List of differences between PSE 40 and PSE30

A lot of users are asking what are the differences between PSE 30 and PSE 40.
This Thread provides information on this subject. First, you will find information copied from the section "New Features" of the useful "Adobe Photoshop Elements 4.0 User Guide". Then later on, you might find additional information on the same subject provided by users of PSE.
--- Start of copy of information in the PSE 4.0 User Guide ----
1 What's new in PSE 4.0
1.1 Editing and selection
1.1.1 Magic Selection Brush tool
Easily and accurately select portions of your photos using this new tool in either Standard Edit and Quick Fix. Simply scribble or place dots on the object you want to select -no need to precisely outline the object- and Adobe Photoshop Elements selects the object for you. You can add to or subtract from the selection by using additional tools in the options bar. (See User Guide "To use the Magic Selection Brush tool" on page 193.)
1.1.2 Magic Extractor.
Easily select an object in a photo and extract it from its background. Just scribble or place dots on
the object you want to extract; then scribble or place dots on the background, and Photoshop Elements separates the object from its background. This tool is perfect for creating composites or scrapbook images. (See User Guide "To use the Magic Extractor" on page 194.)
1.1.3 Skin tone adjustment
Click an area of skin and watch the tonal balance of all colors in the photo improve. If you
want, you can also manually adjust the color by using color sliders. (See User Guide "To adjust the color of skin tone" on page 224.)
1.1.4 Red eye removal
Automatically remove red eye during import, or select one or more files and easily remove red eye
in either the Organizer or the Editor. (See User Guide "To remove red eye" on page 249.)
1.1.5 Defringe
Automatically remove the colored specs or halo around the edges of a selection. (See User Guide "To defringe a Selection" on page 200.)
1.1.6 Straighten tool
Straighten and crop crooked photos by drawing a horizontal or vertical line in the image. Photoshop
Elements aligns the photo to that line. (See User Guide "To straighten an image" on page 243.)
1.1.7 WYSIWYG font menu
What you see is what you get -see what each font looks like from within the font menu. (See
User Guide "To choose a font family and style" on page 332.)
1.2 Sharing and printing
1.2.1 One-click printing (US, Canada, Japan only)
Order prints and professional hardbound photo books directly from Photoshop Elements simply by dragging the items to the Order Prints palette. (See User Guide "To use the Order Prints palette (US, Canada, Japan only)" on page 401.)
1.2.2 Slide shows on TV
If you have Windows¨ XP Media Center 2005 installed, you can view your Photoshop Elements
slide shows on your TV and navigate using your TV remote control. (See User Guide "To output a slide show" on page 354.)
1.3 Tagging and organizing
1.3.1 Face tagging
Select a group of photos and let Photoshop Elements isolate and display all the faces so that you can
quickly tag them. The Find Faces dialog box displays thumbnails of each face until you tag it. (See User Guide "To automatically find faces for tagging" on page 101.)
1.3.2 Search by metadata
Search for a variety of metadata criteria, such as file name, file type, shutter speed, camera
model, date, and tags. You can search on multiple criteria at once. (See User Guide "To find photos by details (metadata)" on page 89.)
1.3.3 PDF support
Manage and tag PDF files in the Organizer. PDF files remain intact as one file that you can tag. Open
the PDF in the Editor to extract individual pages. (See User Guide "To open a PDF file" on page 148.)
--- Continuation in next Post of this Thread ----

--- Continuation from previous Post -----
2 What's changed in PSE 4.0
2.1 Editing and selecting
2.1.1 Crop tool
Freely change image size boundaries while cropping an image. When you're happy with your crop marks,
click the Commit button , which is now conveniently located at the bottom right corner of the crop border. (See User Guide "To crop an image" on page 240.)
2.1.2 Paragraph text
Create paragraph text by dragging a border with the Text tool. The text you enter inside the border
wraps to remain inside the boundaries. (See User Guide "To add text" on page 329.)
2.1.3 Quick Fix
Use the newly enhanced automatic correction options for the most common photo flaws. (See User Guide "To correct color in Quick Fix" on page 207.)
2.1.4 Easier color management
Easily get the color you expect when printing. N ew options and improved embedded
profile support streamline color management. (See User Guide "About color management" on page 236.)
2.1.5 Advanced camera raw
Fine tune exposure and lighting by working with the raw data from your digital camera, and
easily export photos to the universal DNG format. (See User Guide "About camera raw image files" on page 159.)
2.1.6 Artifact reduction
Quickly remove noise caused by shooting in low light or with ISO camera settings by using the
new Remove JPEG Artifacts option in the Noise filter. (See User Guide "Reduce Noise" on page 289.)
2.2 Sharing and printing
2.2.1 Multimedia slide shows
Create feature-rich slide shows with all the new tools and options available in the Slide Show
Editor:
a) Gracefully move from one image to another by adding interesting transitions between each slide. You can choose from over 50 transitions, such as dissolves and doors. (See User Guide "To add and edit transitions" on page 352.)
b) Add text and graphics with the click of a button. (See User Guide "To add text to a slide" on page 348 and "To add clip art graphics to a slide" on page 347.)
c) Make your slide show feel more like a video by panning and zooming your slides. For instance, you can pan from a face on the left side of an image to a face on the right side of the image. (See User Guide "To set pan and zoom" on page 350.)
d) Add background music, make the duration of your slides match the duration of your audio, and narrate your slides all with the click of a button. (See User Guide "To add music to a slide show" on page 347 and "To add narration to a slide" on page 350.)
e) Quickly reorder or edit your slides without leaving the Slide Show Editor. (See User Guide "To reorder slides" on page 346.)
f) Preview anytime by clicking the Preview button, and then output your slide show by burning a DVD (if you have Adobe ' Premiere' Elements installed), sending it in e-mail, sharing it online, or sending it to your TV. (See User Guide "To output a slide show" on page 354.)
2.2.2 Photo mail
Turn plain e-mail into theme-based Photo Mail with enhanced and easier to use captions. (See User Guide "To send a photo using Photo Mail" on page 407.)
2.2.3 Desktop wallpaper
Create original desktop wallpaper using multiple photos. (See User Guide "To use photos as desktop
Wallpaper" on page 367.)
2.2.4 Creations
Create your own cards, calendars, and photo albums, and then print them on your printer, upload them
to the web, or burn them to CD. (See User Guide "About creations" on page 343.)
2.3 Viewing, tagging, and organizing
2.3.1 Faster download
Use the enhanced Photo Downloader to quickly download photos from your digital camera and
mobile phone, even when Photoshop Elements is not running. (See User Guide "To get photos from a digital camera or card reader" on page 62.)
2.3.2 Full Screen and Side By Side View
View your photos in full screen without the clutter of command menus and tools.
(See User Guide "Viewing photos at full screen or side-by-side" on page 76.)
2.3.3 Automatic organization and view options
View your photos as arranged automatically by date, or use the intuitive
Date View or the enhanced Folder Location view. (See User Guide "To sort files in the Photo Browser" on page 71.)
2.3.4 Address book
Import your addresses from Microsoft Outlook address book or vCards. (See User Guide "Using the contact Book" on page 404.)
2.3.5 Captions
Add captions to multiple photos at once. Open and edit audio captions by simply clicking the Audio
icon in thumbnail view in the Photo Browser. (See User Guide "To add captions to files" on page 123 and "To add audio to a photo" on page 124.)
--- End of Information Copied from the Adobe PSE 4.0 User Guide

What is difference between sy-tabix and sy-index.

SAP Seniors,
Can you please let me know what is difference between sy-index and sy-tabix.
I read the SAP help, it is confusing for me. it looks like both are same from help. please help me.
Thank you
Anitha.

HI,
Here is a brief description of difference between SY_TABIX and SY_INDEX and using them with several conditions.
SY-TABIX
Current line of an internal table. SY-TABIX is set by the statements below, but only for index tables. The field is either not set or is set to 0 for hashed tables.
APPEND sets SY-TABIX to the index of the last line of the table, that is, it contains the overall number of entries in the table.
COLLECT sets SY-TABIX to the index of the existing or inserted line in the table. If the table has the type HASHED TABLE, SY-TABIX is set to 0.
LOOP AT sets SY-TABIX to the index of the current line at the beginning of each loop lass. At the end of the loop, SY-TABIX is reset to the value that it had before entering the loop. It is set to 0 if the table has the type HASHED TABLE.
READ TABLE sets SY-TABIX to the index of the table line read. If you use a binary search, and the system does not find a line, SY-TABIX contains the total number of lines, or one more than the total number of lines. SY-INDEX is undefined if a linear search fails to return an entry.
SEARCH <itab> FOR sets SY-TABIX to the index of the table line in which the search string is found.
SY-INDEX
In a DO or WHILE loop, SY-INDEX contains the number of loop passes including the current pass.
Hope this helps.
Thank you,
Pavan.

Difference between sy-tabix and sy-index?

tell me about sy-tabix and sy-index?what is the difference between sy-tabix and sy-index?
Moderator Message: Please search before posting. Read the [Forum Rules Of Engagement |https://wiki.sdn.sap.com/wiki/display/HOME/RulesofEngagement] for further details.
Edited by: Suhas Saha on Jun 18, 2011 5:33 PM

HI,
Here is a brief description of difference between SY_TABIX and SY_INDEX and using them with several conditions.
SY-TABIX
Current line of an internal table. SY-TABIX is set by the statements below, but only for index tables. The field is either not set or is set to 0 for hashed tables.
APPEND sets SY-TABIX to the index of the last line of the table, that is, it contains the overall number of entries in the table.
COLLECT sets SY-TABIX to the index of the existing or inserted line in the table. If the table has the type HASHED TABLE, SY-TABIX is set to 0.
LOOP AT sets SY-TABIX to the index of the current line at the beginning of each loop lass. At the end of the loop, SY-TABIX is reset to the value that it had before entering the loop. It is set to 0 if the table has the type HASHED TABLE.
READ TABLE sets SY-TABIX to the index of the table line read. If you use a binary search, and the system does not find a line, SY-TABIX contains the total number of lines, or one more than the total number of lines. SY-INDEX is undefined if a linear search fails to return an entry.
SEARCH <itab> FOR sets SY-TABIX to the index of the table line in which the search string is found.
SY-INDEX
In a DO or WHILE loop, SY-INDEX contains the number of loop passes including the current pass.
Hope this helps.
Thank you,
Pavan.

What is difference between sy-index and sy-tabix and where both are using ?

what is difference between sy-index and sy-tabix and where both are using ?

hi nagaraju
sy-tabix is in Internal table, current line index. So it can only be used while looping at the internal table.
sy-index is in Loops, number of current pass. This you can use in other loop statements also (like do-enddo loop, while-endwhile)
SY-INDEX is a counter for following loops: do...enddo, while..endwhile
SY-TABIX is a counter for LOOP...ENDLOOP, READ TABLE...
Here is an example from which you can understand the difference between sy-tabix and sy-index.
Itab is an internal table with the following data in it.
id Name
198 XYZ
475 ABC
545 PQR.
loop at itab where id > 300.
write :/ itab-id, itab-name , sy-tabix, sy-index.
endloop.
My output will be :
475 ABC 2 1
545 PQR 3 2
Sy-tabix is the index of the record in internal table.
sy-index gives the no of times of loop passes.
So, for the first record in the output (475 ABC), 2 is the index of the record in internal table and as it is first time loop pass occured, sy-index value is 1.
Regards,
navjot
award points

Difference between sy-uline and uline

Hi All,
Any one of you please update me what is the difference between sy-uline and uline. Also when i give sy-uline in top-of-page event it gives error.
Thanks
sankar

with ULINE u can specify the position from where the ULINE should start
corresponds to WRITE AT 3(10) SY-ULINE.
ULINE AT 3(10) NO-GAP will supress the spacess after the under line
ex : 1
uline at 4(10).
write : / 'My Program'.
uline at 4(10).
ex : 2
write : 'My Program' , sy-uline.

What is difference between bus.Area and plant

dear experts,
what is difference between bus.Area and plant?
thanks
Rajakarthik.

Hi
Plant and Business Area are not the same.
Business Areas are configured in FI module as per the Product lines or geographical operations basis.
Where as The plants created in the logistics (General) module are assigned to the company code. That means all transactions taking place in the plants are posted to the attached company code in SAP FI.
You can post a business area to several company codes and use it for cross-company-code reporting.
The R/3 System uses a combination of plant and division to assign the relevant business area. When you use the R/3 System to automatically draw up accounts for business areas, you can assign only one business area to a combination of plant and division. Plants and divisions can be assigned and combined in several different ways.
http://help.sap.com/saphelp_46c/helpdata/en/5d/a77d80ec1111d2bc1000105a5e5b3c/content.htm
Re: Business Area and Plant
Regards

What is difference between TEXT mode and BINARY mode?

Hi,
          What is difference between TEXT mode and BINARY mode? In TEXT mode what is "ENCODING DEFAULT".
OPEN DATASET wl_filename FOR INPUT
                          IN TEXT MODE ENCODING DEFAULT.
OPEN DATASET wl_filename FOR INPUT
                          IN BINARY MODE .

Hi vishnu,
1. files like .TXT files are considered to be text,
   and other files like .EXE . DOC etc are binary files.
2. In text files, after each line, there are two
   internal binary characters
one for line feed and another one for newline.
3. But, we don't have any meaning for it,
   when we view such files in notepad, for eg.
   Hence, to only get the understandable content,
   we should open such TXT files, in text mode.
(we can also open them in binary mode,
but we will get two extra characters after each line,
   and such two extra characters are meaningless
for interpreting the text)
4. In binary mode, each byte by byte is considered,
   without any meaning.
regards,
amit m.

What is difference between interactive list and interactive reports?

what is difference between interactive list and interactive reports?

hi check this..
interactive report/list means any input(double click or single click or user command ) on the screen will results a new screen with the corresponding fields....this is upto 20 levels only check this..
report .
start-of-selection.
write:/ 'this is the source list'.
at line-selection .
if sy-lsind = 1 .
write:/ ' this is the 1st list'.
elseif.
if sy-lsind = 2 .
write:/ ' this is the 2 list'.
if sy-lsind = 3 .
write:/ ' this is the 3 list'.
if sy-lsind = 4 .
write:/ ' this is the 4 list'.
if sy-lsind = 5 .
write:/ ' this is the 5 list'.
if sy-lsind = 6 .
write:/ ' this is the 6 list'.
if sy-lsind = 7 .
write:/ ' this is the 7 list'.
if sy-lsind = 8.
write:/ ' this is the 8 list'.
if sy-lsind = 9 .
write:/ ' this is the 9 list'.
if sy-lsind = 10 .
write:/ ' this is the 10 list'.
endif.
regards,
venkat

Difference between open loop and closed loop mode when finding the index on a stepper motor axis.

I have a test system which uses a PXI-7352 motion controller with a MID-7602 stepper motor drive to position a 200 step/revolution stepper motor with an attached 1000 line encoder. The MID-7602 is configured for 64 microsteps per step, giving 12,800 microsteps and 4000 encoder counts per revolution. The system is controlled using LabView 7.1 and NI-Motion 6.13. To home the motor, I've defined a sequence in MAX which first finds the reverse limit switch and then moves forward to the encoder index pulse.
When finding its reference in open loop mode, the system its reference at the same microstep each time. When findings its reference in closed loop mode, the system finds its reference somewhere within about a 20 microstep wide range.
I hope somebody out there with more experience with this controller can describe the difference between finding the encoder index in open loop mode and finding the encoder index in closed loop mode.
Thanks,
Mark Moss

Hello Mark,
I suspect that the behavior you are experiencing has today
with the resolution difference between your encoder and your
microstepping. Let me illustrate with an
example:
Example Setup
Stepper
Motor
NI
Motion Controller
10
steps per encoder pulse (Every 10 steps the controller gets an encoder
pulse, therefore positions 0-9 all appear to be 0 to the controller)
The
system has a maximum of 3 pull in moves set
Open Loop Scenario
The
system is commanded to go to position 9.
The
controller sends out 9 pulses.
The
motor moves to position 9.
Closed Loop Scenario
The
system is commanded to go to position 9.
The
controller sends out 9 pulses.
The
motor moves to position 9.
The
controller checks its position and sees that it is still at position 0
because it has not received an encoder pulse.
Because
the controller thinks it is still at position 0, it sends another 9 pulses
as its first pull in move.
The
motor moves to position 18.
The
controller checks its position and sees that it is at position 10 because
it has only received one encoder pulse.
Because
the controller thinks it is still at position 10, it sends1 reverse pulse
as its second pull in move.
The
motor moves to position 17.
The
controller checks its position and sees that it is at position 10 because
it has only received one encoder pulse.
Because
the controller thinks it is still at position 10, it sends and additional
single reverse pulse as its third pull in move.
The
motor moves to its final position of 16.
I believe something similar is happening with your
application as it looks for the index pulse.
Because the controller does not compensate for what it perceives as
position error in open loop mode, the motor always goes to the same commanded
position. In closed loop mode, the motor
is bouncing around inside the single index encoder pulse trying to find a
certain position.
There are several recommendations I can make towards
correcting this behavior. These
recommendations are in order of effectiveness:
Setup
your system so that there are more encoder counts per revolution than
steps per revolution.
Turn
off pull-in moves by setting them to 0 in MAX.
Use an
open loop configuration.
Play
around with the pull in window in MAX.
Regards,
Luke H

What is the difference between list display and grid display in alv report

Hai genious
i am a new of the abap, i dont know the alv report, i have a small doubt, can u please tell me what is the main difference between list display and grid display in alv report
thanks&regards
chinnu

Hi ,
1. For all practical purposes, they are the same.
2. Some differences:
a) from abap coding point of view,
alv list is done with Function modules,
alv gris can also be done with FM,
but can also be done using OO concepts.
b) Alv grid (using oo concept) requires
designing the screen layout .
Hence, in one screen, we can show more
then one alv grid
(we cannot show more than
one alv list on one screen)
c) ALV grid uses ActiveX controls
present on the Presentation Server.
Hence, it consumes More Memory
on the presentation server.
d) ALV LIST is Display Only.
Whereas
ALV Grid Can Be made EDITABLE for entry purpose.
e) In alv grid, these options are possible,
but not in alv list.
without horizontal lines
without vertical lines
without cell merging during sorts
display total lines above the entries
I hope it helps.
Regards,
Mamta
Edited by: Mamta Verma on Nov 27, 2008 6:41 AM

The difference between FIELD-SYMBOL and normal DATA TYPE

Dear experts,
Please see the example below, both are output the same result.
DATA: EXTERNAL_RECORD(4000),
      POSITION TYPE I,
      LENGTH TYPE N,
      ENTRY TYPE STRING.
EXTERNAL_RECORD = '0005Smith0007Edwards0005Young'.
DO.
LENGTH = EXTERNAL_RECORD+POSITION(4).
IF LENGTH = 0.
    EXIT.
ENDIF.
ADD 4 TO POSITION.
MOVE EXTERNAL_RECORD+POSITION(LENGTH) TO ENTRY.
WRITE ENTRY.
ADD LENGTH TO POSITION.
IF POSITION >= 4000.
    EXIT.
ENDIF.
ENDDO.
--OR It can be written as--
DATA: EXTERNAL_RECORD(4000),
      POSITION TYPE I,
      LENGTH TYPE N.
FIELD-SYMBOLS <ENTRY>.
EXTERNAL_RECORD = '0005Smith0007Edwards0005Young'.
DO.
LENGTH = EXTERNAL_RECORD+POSITION(4).
IF LENGTH = 0.
    EXIT.
ENDIF.
ADD 4 TO POSITION.
ASSIGN EXTERNAL_RECORD+POSITION(LENGTH) TO <ENTRY>.
WRITE <ENTRY>.
ADD LENGTH TO POSITION.
IF POSITION >= 4000.
    EXIT.
ENDIF.
ENDDO.
Is there any special circumstances we need to use FIELD-SYMBOL?
Why is FIELD-SYMBOL is introduce in the first place?
Kindly advice with example.
Thanks in advance for those who can help me on this.

HI,
You can use field symbols to make the program more dynamic. In this example the name of a table control is substituted by a field symbol. Thus you cal call the form with any internal table, using the name of the table control as a parameter.
Example
form insert_row
using p_tc_name.
field-symbols <tc> type cxtab_control. "Table control
assign (p_tc_name) to <tc>.
insert 100 lines in table control
<tc>-lines = 100.
Field symbols allow you to:
**     Assign an alias to a data object(for example, a shortened
        name for data objects structured through several hierarchies
        - <fs>-f instead of rec1-rec2-rec3-f)
**     Set the offset and length for a string variably at runtime
**     Set a pointer to a data object that you determine at runtime (dynamic ASSIGN)
**     Adopt or change the type of a field dynamically at runtime
**     Access components of a structure
**     (from Release 4.5A) Point to lines of an internal table
        (process internal tables without a separate work area)
Field symbols in ABAP are similar to pointers in other programming
languages. However, pointers (as used in PASCAL or C) differ from ABAP
field symbols in their reference syntax.
The statement ASSIGN f to <fs> assigns the field f to field
symbol <fs>. The field symbol <fs> then "points" to the
contents of field f at runtime. This means that all changes to the
contents of f are visible in <fs> and vice versa. You declare
the field symbol <fs> using the statement FIELD-SYMBOLS: <fs>.
Reference syntax
Programming languages such as PASCAL and C use a dereferencing symbol
to indicate the difference between a reference and the object to which
it refers; so PASCAL would use p^ for a pointer instead of p, C would
use *p instead of p. ABAP does not have any such dereferencing symbol.
**     In PASCAL or C, if you assign a pointer p1 to a pointer p2,
you force p1 to point to the object to which p2 refers (reference semantics).
**     In ABAP, if you assign a field symbol <fs1> to a field
symbol <fs2>, <fs1> takes the value of the data object to
which <fs2> refers (value semantics).
**     Field symbols in ABAP are always dereferenced, that is,
they always access the referenced data object. If you want to
change the reference yourself in ABAP, you can use the ASSIGN statement
to assign field symbol <fs1> to field symbol <fs2>.
Using field symbols
You declare field symbols using the FIELD-SYMBOLS statement.
They may be declared either with or without a specific type.
At runtime you assign a field to the field symbol using the ASSIGN
statement. All of the operations on the field symbol act on the field
assigned to it.
When you assign a field to an untyped field symbol, the field symbol
adopts the type of the field. If, on the other hand, you want to assign
a field to a typed field symbol, the type of the field and that of the
field symbol must be compatible.
A field symbol can point to any data object and from Release 4.5A,
they can also point to lines of internal tables.
The brackets (<>) are part of the syntax.
Use the expression <fs> IS ASSIGNED to find out whether the field
symbol <fs> is assigned to a field.
The statement UNASSIGN <fs> sets the field symbol <fs> so
that it points to nothing. The logical expression <fs>
IS ASSIGNED is then false. The corresponding negative expression
is IF NOT <fs> IS ASSIGNED.
An unassigned field symbol <fs> behaves as a constant with
type C(1) and initial value SPACE.
MOVE <fs>
TO dest     Transfers the initial value SPACE to the variable dest
MOVE 'A' to <fs>
Not possible, since <fs> is a constant
(runtime error).
To lift a type restriction, use the CASTING addition in the
ASSIGN statement. The data object is then interpreted as though
it had the data type of the field symbol. You can also do this
with untyped field symbols using the CASTING TYPE <type> addition.
The danger with pointers is that they may point to invalid areas.
This danger is not so acute in ABAP, because the language does not
use address arithmetic (for example, in other languages, pointer p
might point to address 1024. After the statement p = p + 10, it would
point to the address 1034). However, the danger does still exist, and
memory protection violations lead to runtime errors.
A pointer in ABAP may not point beyond a segment boundary. ABAP does
not have one large address space, but rather a set of segments.
Each of the following has its own segment:
*     All global data
*     All local data
*     Each table work area (TABLES)
*     Each COMMON PART
You should only let field symbols move within an elementary field or
structure where ABAP allows you to assign both within the global data
and beyond a field boundary.
Rgds
Umakanth

Difference between noise margin and noisy line

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