FarSync BERT

FarSync BERT - Additional Configuration

Further additional configuration options are available via the Additional Configuration dialog which is displayed on pressing the More button (shown below)

More and Start Buttons 

Note that pressing the More button during a test will cause the test to stop. Simply press the Start button (shown above), after closing the More dialog, to start a new test using the new settings.

The Additional Configuration options that are displayed will change according to the current Test Function setting. For the BER tests, General, User Patterns and Multi-Drop tabs are displayed as shown below.

Additional Configuration BER

For RTD tests, General and Round Trip Delay tabs are displayed as shown below.

Additional Configuration Round Trip Delay

Please select the required Test Function before clicking on the More button to access the appropriate options.

General - Port

The FarSync BERT uses one FarSync (port). If you intend to only ever use one FarSync Flex (physical instance) then you should be able to leave the Port parameter as its default value (Any) and skip the rest of the discussion regarding the Port parameter.

If, however, you want to use a FarSync T2Ee card (which supports 2 ports) or, alternatively, multiple FarSync Flexes

then read on.

Multiple FarSync devices can be installed in the PC. Each instance will have a unique index associated with it. This index number is displayed in Device Manager next to a prefix of "SDCI" e.g.

 

 

To access this display, use Start-Computer(right-click)-Manage-Device Manager

By default, each index is associated with a physical instance of a FarSync device (Flex or T2Ee). Therefore, in the case of the Flex, if you start by installing FlexA, this will appear as SDCI0. If you then install another Flex, FlexB, this will be assigned an index of 1 i.e. SDCI1. If you remove FlexA and FlexB, then whenever you subsequently insert either Flex, FlexA will always appear as SDCI0 and FlexB as SDCI1 - regardless of the order you use to insert them; or if, for example, you only insert FlexB - it will still appear as SDCI1 even though FlexA (SDCI0) is not inserted.  An alternative (port-centric) mapping scheme can be used but this should not normally be necessary (see  "Why do I need to reinstall drivers when I replace one FarSync Flex with another?" in FarSync Flex FAQ).

By default, the FarSync BERT's Port parameter is set to Any and will consequently simply use the first FarSync port that it detects. This is a suitable setting if you only ever have one Flex physical inserted into the machine at one time. Even if, for example, you replace FlexA(SDCI0) with FlexB(SDCI1), the setting does not need to change since the FarSync BERT will just use the first one that it locates.

If, however, you have multiple Flexes inserted at the same time, one instance of FarSync BERT will need to be started for each Flex. Once the FarSync BERT has been started you need to select the port it should use. You do this by setting the Port parameter to the Flex's index number. So, for instance, FlexA would be selected by setting Port to 0; FlexB by setting Port to 1.

When using multiple Flexes, a single Port Setting value will persist for all FarSync BERT instances. So if you exit the BERT and restart it, you should then reset the Port parameter to the required setting.

In the case of the FarSync T2Ee, again, each instance will appear in Device Manager with its own unique index number e.g. SDCI0, SDCI1 etc. However, since the FarSync T2Ee supports multiple ports, if you want to select a specific port to be used by the FarSync BERT, then you need to configure not only the SDCI index number but also the FarSync port number on that T2Ee card e.g. 0/A or 0/B. Alternatively, as before, you can leave the FarSync BERT's port selection as Any and then the BERT will simply choose to use the first detected port.

 

General - Encoding

The Encoding parameter defines the type of data encoding to be used on the line connected to this port when configured for SYNC mode. When using the port in ASYNC mode, you should always set the encoding option to NRZ. Note that for the Flex V1, the maximum line rate for NRZI, FM0 and FM1 modes is normally 512Kbps. However, it does additionally support 768Kbps and 1536Kbps in these modes. FM0/1 and (D)MAN are supported by the FarSync T2Ee between rates of 1200bps and 10Mbps. NRZI, FM0/1 and (D)MAN are supported by the FarSync Flex V2, and above, between rates of 100bps and 2Mbps. In High Speed mode the rates are between 100bps and 10Mbps.

For detailed information on the precise card/encoding-specific rates that are supported, refer to the FarSync FAQ.

Note that the use of MK and SP patterns is not recommended if you are using Manchester (MAN) encoding.

Default: NRZ

Supported encoding schemes:

  T2Ee Flex (V1) Flex (V2)
NRZ ü ü ü
NRZI û ü ü
FM0 ü ü ü
FM1 ü ü ü
MAN (Manchester) ü û ü
DMAN (Differential Manchester
/Conditioned Diphase)
ü û ü

 

General - NRZI Clocking

Although some clocking information is included in the NRZI bitstream, it may not be adequate enough to allow for reliable clock recovery.

The NRZI Clocking option allows for a separate one times clock to be provided with the encoded data, thus enhancing reliability.

Default: Disabled

Supported by:

T2Ee Flex (V1/V2)
û ü

 

General - Invert Rx Clock

The Invert Rx clock option is used to change the phase of the internal clock by 180 degrees (for received data). If

then inverting the clock may solve the problem.

Default: Disabled

 

General - Advanced Clocking

This option is used to specify whether Advanced Clocking is used on the FarSync port. When the Advanced Clocking option is selected, it overrides the Clocking setting and disables the (C) button on the Front Panel.

When Advanced Clocking is selected, the values are set according to keys/values in the Registry. If you wish to use Advanced Clocking then please contact FarSite support at support@farsite.com for further information.

 

General - Termination

This option is used to specify whether termination is used on the FarSync port.

Default: Disabled

 

General - Data Bits (BER only)

This parameter is used to configure the number of async data bits (8,7,6 or 5) in each character. This is only applicable when the BERT is set in ASYNC mode and is thus not supported when using the FarSync T2Ee.

Default: 8

Supported by:

T2Ee Flex (V1/V2)
û ü

 

General - Parity (BER only)

This parameter is used to configure the async parity setting (NONE, ODD, EVEN, MARK or SPACE) for the FarSync port. This is only applicable when the BERT is set in ASYNC mode and is thus not supported when using the FarSync T2Ee.

Note: The use of SPACE is typically not recommended due to, in some cases, the start/parity bits not always being uniquely identifiable which can in turn lead to problems achieving synchronisation.

Default: None

Supported by:

T2Ee Flex (V1/V2)
û ü

 

General - Stop Bits (BER only)

This parameter is used to configure the number of async stop bits (1 or 2) between each character. This is only applicable when the BERT is set in ASYNC mode and is thus not supported when using the FarSync T2Ee.

Default: 1

Supported by:

T2Ee Flex (V1/V2)
û ü

 

General - Flow Control (BER only)

This parameter is used to configure the type of async flow control (NONE, RTS-CTS or XON-XOFF) used on the FarSync port . This is only applicable when the BERT is set in ASYNC mode and is thus not supported when using the FarSync T2Ee.

Default: Off

Supported by:

T2Ee Flex (V1/V2)
û ü

 

General - Display Rates (BER only)

The FarSync BERT results pane can display the rates achieved either as Ratios or Percentages. Set this parameter to the format you require.

Rates shown as Ratios

 

Rates shown as Percentages

General - Burst Mode (BER only)

By default the FarSync BERT expects data to be received at a constant rate based on the configured line rate. In some test cases, the receive data arrives in bursts. In synchronous burst modes, the associated clock is idle in between bursts. In this case the Burst Mode parameter should be set to avoid the FarSync BERT reporting errors when the idle periods are detected.

General - Audible Alerts (BER only)

By default the FarSync BERT will report errors only via its statistics displays/output. However, if the Audible Alerts option is enabled, the BERT will also sound alerts; one to indicate errors and one to indicate any state transitions to LOS. The audible alert rate will always be greater than or equal to 1 second. i.e. each audible alert indicates one or more errors have occurred within the last second.

General - Auto Invert (RIV) (BER only)

Occasionally the equipment and/or cabling being tested by the BERT has been wired incorrectly such that the data lines are actually inverted. If the Auto Invert option is enabled, the BERT will check for this and automatically invert the received data (if still in LOS after 2 secs) to determine if synchronisation can then be established. The BERT will toggle between inverted and non-inverted Rx mode, every 2 seconds until synchronisation has been achieved. Note that whenever the BERT is inverting the receive data, the RIV indicator will be lit.

General - Enable Logging

If this option is selected, the FarSync BERT outputs a summary of its tests in a log file as described in the Logging section. If this option is deselected, no writing to the log file takes place. Logging is performed for both BER and RTD modes.

General - Maximum Log File Size

 By default the maximum size of this file is set to be 1MB. This limit can be configured via the Maximum Log File Size parameter. This can be set to any value up to 1GB. A value of 0 is used to configure an unlimited size.

General - BERT Support (BER only)

The FarSync BERT can optionally be used with its BERT engine being run in hardware mode on the FarSync Flex device itself i.e. instead of it being run on the host PC. This enables the FarSync Flex to support extended line rates. The maximum rate supported by the FarSync Flex when using software mode is 2Mbps. When hardware mode is used the maximum rate is 16Mbps. Hardware mode is only supported on HighSpeed-V2 Flex devices e.g. not FarSync T2Ee or earlier Flex devices. This parameter can normally be left as “Hardware” since, if hardware support is not available on the selected device then, it will automatically revert to software mode.

User Patterns - Pattern Name (BER only)

By default, the pattern names are marked as USR1 to USR8 where USR denotes User. The default pattern names can be changed by clicking on the name and by typing in a new value. Pattern names must be unique, uppercase and between 1 to 4 characters.

Additional Configuration - Pattern Name

User Patterns - Pattern Filename

A pattern filename can be typed in or selected using the File Browser Dialog. To add a new filename, click anywhere within the <filename> box and type in the path to the filename or click on the button that appears in the <filename> box and select the desired file using the File Browser Dialog.

User Patterns - Pattern Filetype

The two filetypes which are supported are hexadecimal and binary. A hexadecimal filetype is expected to be of the format as shown in the diagram below.

User Patterns - Hex Format

A binary filetype is expected to be of the format as shown in the diagram below (as viewed in a binary viewer).

User Patterns - BIN Format

Muti-Drop - Enable Multi-Drop Testing

When the checkbox is selected, the BERT will enter the Multi-Drop test mode. For further information about the Multi-Drop mode, see the Multi-Drop section. Once Multi-Drop mode has been selected, the other Multi-Drop options on the tab can be configured.

Additional Configuration - Multi-Drop

Multi-Drop - Designation

Each node in the Multi-Drop test must be configured to either a ‘Master’ or a ‘Slave’. When configured to be a master, the applicable ‘Master’ configuration options become available for configuration. When configured to be a slave, the ‘Slave’ options become available for configuration.

Multi-Drop - Slave Id

Enter the desired Slave Id for this Multi-Drop node. Each Slave Id on the Multi-Drop network must be unique. Slave Id’s must be in the range from 1 to 247.

Multi-Drop - Slaves To Poll

Enter a list of slaves to poll. Use spaces or commas to separate individual entries, e.g. 1 2 3 or 1,2,3 or 1, 2, 3 and a hyphen to set a range, e.g. 1-3 or any combination of the two, e.g. 1 2 4-6.

Slaves can be entered in any order (except ranges), but when the list is saved, they will be sorted and any duplicates will be removed.

Multi-Drop - Message Type

Currently, the only supported message type is ‘Echo’. This Message Type will be echoed by the slave receiving the message.

Multi-Drop - Payload Length

The Payload Length defines the number of bytes used to carry the pattern to each of the slaves. The Payload Length must be between 1 and 249 bytes.

Multi-Drop - Poll Unresponsive Slaves

If a slave fails to echo back a message (before a timeout), it will be excluded from the list of slaves to poll unless this option is selected.

Note that if this option isn’t selected, you should make sure that you start the slaves before starting the master, otherwise the test will stop when the master fails to get the response from the slave.

Round Trip Delay - Payload Length

Sets the length of the payload (in bytes). The payload length must be between 1 and 31 bytes.

Additional Configuration - Round Trip Delay

Round Trip Delay - Transmit Delay

Sets the delay (in milliseconds) between the receipt of one packet and the transmission of the next. If the value is set to 0, the next packet is transmitted as soon as the previous one is received. The delay must be between 0 and 3,600,000 (1 hour).

Round Trip Delay - Receive Timeout

Sets the receive timeout (in milliseconds). If a transmitted packet is not received within this time it is deemed to have been lost (even if it subsequently arrives). The next packet will then be transmitted according to the configured Transmit Delay value.

Note that the Receive Timeout timer starts before the payload is clocked out onto the line. This means that the value that you set for Receive Timeout should include the time it takes for the data to be clocked out onto the line and also the Round Trip Delay time. An example of how long it takes to clock a payload length of 30 bytes out at 300 bps is shown below:

   30 * 8(bits) / 300bps * 1000 = 800ms

So in this example the Receive Timeout should be set to 800ms + expected Round Trip Delay time + a margin.

For further details on how FarSync BERT reports its results click here

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