FarSync BERT

FarSync BERT - Results

FarSync BERT outputs the results of its tests in 3 ways

Compact View Results

Whilst the test is running the Errors pane will display the number of Bit Errors, Block Errors, Errored Seconds, Framing Errors, Parity Errors or All Errors that have occurred during the test. The Secs pane displays the total number of seconds that the test has been running for.

Compact Results 

Pressing the Errors button (as shown in the diagram below) causes the Errors pane to switch between BIT, BLOCK, SECONDS, PARITY, FRAME and ALL error counter values.

Errors Button 

If the errors or secs value overflows then the Overflow Indicators are highlighted. Note that the actual value can be obtained from the statistics/results table (see below). The overflow condition can be reset by using the Reset button.

When the FarSync BERT is unable to synchronise with the incoming data (e.g. due to a physical break in the line, the wrong test pattern configured etc.) the Loss-of-Sync (LOS) indicator will be highlighted.

The interface signals states (DTE and DCE), as well as the RIV indicator, are updated in real-time in the Signals pane whilst the test is running.

Statistics/Results Table

At any point the Table button can be used to display a table of statistics for the current (or most recent) test. Depending on the Test Function and Multi-Drop settings, one of three possible results tables will be displayed.

BER Results

This statistics/result table displays industry-standard count values (e.g. ITU-T G.821) which help indicate the current quality of the line:

The following rate values are also displayed:

To return to the compact view (i.e. without the statistics table displayed) press the Table button once more.

Multi-Drop Results

Multi-Drop Results

The Multi-Drop Results Dialog displays the results for each slave being polled and also displays the Total results which are the combined results of all the slaves.

The calculations used for the Total results are as follows:

The ES, SES, AS and LOS Counts and rates are based on ‘whole second’ values and so their calculations differ somewhat from those used to calculate the Bit and Block Rates.

Note that the LOS Count in the Multi-Drop test is the number of seconds the slave has lost sync. This differs from that displayed in the normal BER test which shows the number of times sync has been lost.

If a slave is out of sync, the results for that slave are highlighted in red. If a slave has stopped responding altogether, (i.e. it’s not echoing back any data), it is highlighted in gray.

When the transmitter/receiver is inverted in an attempt to achieve sync, the TIV/RIV text will be displayed in the Inverted column for that slave.

Multi-Drop Results Configuration

The Multi-Drop Results Configuration Dialog can be accessed by double-clicking anywhere on the Multi-Drop Results Dialog.

Multi-Drop Results Configuration

If the Slave List is updated in the Additional Configuration – Multi-Drop tab, the settings for Poll and Show Stats will be retained for any slaves that remain in the list. If new slaves are added to the list, the default is for Poll and Show Stats to be selected.

Round Trip Delay Results

The Round Trip Delay Results are displayed as shown below. The individual Round Trip Delay values are displayed on a chart.

Round Trip Delay Results

where:

The Round Trip Delay results are plotted on a chart. The x-axis shows the Round Trip Delay times (in milliseconds) for the packets and the Y-axis shows the number of occurrences of each time.

Clicking on the chart will cycle through three different graph modes. These are line, spline and column. All three modes show exactly the same data, but in a slightly different format. Depending on the generated data, one display mode may produce a better graph than the others.

Note that as the chart is dynamically generated from the results, it isn’t displayed until the Round Trip Delay values are received during the test. In the case where all packets are lost, no chart is displayed.

Test Startup and Initial Synchronisation

Note that when each test is started there will be an initial period before synchronisation is achieved.

During this initial period

Once synchronisation is achieved for the first time

Subsequent LOS transitions will result in the counters/results being updated accordingly (but will not result in them being reset unless explicitly requested by the user pressing the Reset button).

Test Completion

If the test is setup to run continuously (i.e. with LENGTH set to CONT) then use the Stop button to complete the test when required. If the LENGTH is not set to CONT, this length value determines how many bits to test in the received datastream before completing the test. Note that the count does not start until initial synchronisation is achieved.

Test results are retained until either the test is restarted (by pressing the Start button) or the test is reset at any time (using the Reset button).

Logging

Logging can be enabled by selecting the Enable Logging checkbox in the Additional Configuration – General tab.

If logging is enabled, the results of each test are also logged to the fsbert<device index>.<port index>.log file which can be found in the current user's My Documents folder. [Note that this folder is expected to be found under %HOMEDRIVE%\%HOMEPATH%. If these environment variables have been changed from their normal default values then you should create a My Documents folder in the location referenced by those values]. Alternatively you can set a system environment variable, FSBERTLOGPATH, to point to a folder of your choice, to be used by the BERT to hold its log files.

The log file can grow in size quite quickly. Its maximum size is controlled by the Maximum Log File Size value discussed here. You can optionally manually delete it, as and when required, and a new version will be created on the next logging event. When the Maximum Log File Size has been reached, the fsbert0.0.log file, for instance, is renamed, fsbert0.0.bak.log, and a new fsbert0.0.log created.

If you have multiple FarSync devices installed then the first digit in the filename of the log file produced will match the index of the device used. For an installation with a single FarSync device this value will always be 0. If you are using multiport FarSync devices i.e. a FarSync T2Ee card,  then the last digit in the filename will indicate the port in use i.e. 0=PortA, 1=PortB

BER Logging

This file contains a summary of each test run, and includes:

Multi-Drop Logging

Multi-Drop Logging

The Multi-Drop log is updated twice every second with statistics for each slave being polled and is also updated when significant events occur.

The log entry includes:

Round Trip Delay Logging

Round Trip Delay Logging

The Round Trip Delay log is updated twice every second. A log entry is also made if an unexpected packet is received (late packet) and on a receive timeout (lost packet).

The logged values are described below:

If packets are being logged as late, it indicates that they are being received after the receive timeout has expired. Increasing the receive timeout to a suitably large value will stop this from occurring.

Monitoring

The FarSync Line Monitor is supplied with the FarSync BERT. This application supports real-time monitoring of transmitted and received data as it appears on the line being monitored. To use the FarSync Line Monitor to monitor the FarSync BERT’s traffic the BERT must be run in software mode as configured via the BERT Support option in the Additional Configuration dialog.

Note that when the BERT is running in hardware mode, the FarSync Line Monitor will actually display internal status information being passed back from the FarSync Flex to the host PC.

 

Copyright © FarSite Communications Ltd. 2009-2020