T1/E1 Analysis

File based Record/Playback over FDL


The File based Record/Playback over FDL (FdlFunc) module is an optional application that allows to receive and transmit HDLC frames and signals in *.hdl file format over facility data link (FDL).

  • Receiving HDLC frames and signals in HDL files
  • Transmitting HDLC frames and signals from an HDL file

Syntax Notation

Whenever FdlFuncT1: XXX is used in a command syntax implies that FdlFuncT1:XXX must be used for T1 cards. All the parameters must be entered in the order defined by the syntax. [parm] means that the parameter is optional and can be omitted.

Parm1|Parm2|Parm3 - parameter is mandatory, one of the choices Parm1, Parm2 or Parm3 must be specified

NOTE : T1 cards must be in ESF (193E) mode in order to execute the functions correctly.

  • Displaying command syntax
  • run task "FdlFuncT1:help" #1;

  • Transmission of HDLC frames and signals over FDL from an HDL file

  • Syntax:

    run task "FdlFuncT1:FdlTxFile" using " 'File_Name' CONT|EOF|N_frames [SignalRepeatCount] [FLAGS nFlags] " #Dev;
    run task "FdlFuncT1:FdlTxFile 'File_Name' CONT|EOF|N_frames [SignalRepeatCount] [FLAGS nFlags]" #Dev;


    'File_Name' - name of HDL file in single quotes to transmit CONT - transmit file in round robin fashion (after the last frame transmit the 1st frame)
    EOF - transmit an entire file once
    N_frames - transmit N_frames. Frame means an HDLC frame or a signal.

    If file is shorter than N_frames start transmitting the 1st frame after the last frame till N_frames are transmitted. For example, if file contains 3 frames and N_frame = 12, the file is transmitted in circular fashion 4 times: frames 1,2,3,1,2,3,1,2,3,1,2,3

    SignalRepeatCount = 1 by default, otherwise the signal from the HDL file will be repeated SignalRepeatCount-times. To transmit a signal for a second SignalRepeatCount should be 256; SignalRepeatCount affects only signals which are stored in the HDL file as one byte. Before transmission FF is appended before each transmitted signal. Therefore, transmitting 256 signals is equivalent of transmitting 512 bytes (FF,Sig). FDL transmission rate is 4 kbits/sec. FLAGS nFlags - number of flags (0x7E) between frames to transmit.


    SignalRepeatCount is for one-byte frames representing signals; FLAGS nFlags is number of flags appended to an HDLC frame. Each HDLC frame always has at least one preceding flag. HDLC frame must be at least two bytes long.


    run task "FdlFuncT1:FdlTxFile" using "'c:\test.hdl' 3 Flags 1000" #1 continuous;
    Transmit first three frames on card 1 with 1000 flags between frames

    run task "FdlFuncT1:FdlTxFile" using "'c:\data files\test.hdl' CONT 4096 " #1 continuous;

    Continuously transmit file

    c:\data files\test.hdl' on card 1 with 4096 signal repetition for each signal in the HDL file.

  • Receiving HDLC frames and signals over FDL into an HDL file
  • Syntax: run task "FdlFuncT1:FdlRxFile" using " 'File_Name' FileSize CONT|N_frames_signals "
    run task "FdlFuncT1:FdlRxFile 'File_Name' FileSize CONT|N_frames_signals "


    `File_Name' - name of HDL file in single quotes to saved received frames to
    FileSize - maximum disk file size in bytes
    CONT - record frames in circular fashion, i.e. when the file capacity (size) is reached purge earlier frames.
    N_frames_signals - receive up to N_frames or/and signals

    Repetitive signals are recorded as single one byte long frame in the HDL file. FF is not recorded.


    run task "FdlFuncT1:FdlRxFile" using "'c:\test.hdl' 10000000 100000" #1 continuous;
    receive into file c:\test.hdl (allocate 10MB disk space for the file) up to 100000 frames on card 1.

  • Transmitting user specified HDLC frames or signals over FDL
  • Syntax: run task "FdlFuncT1:FdlTx" using "" #Dev;
    This command starts transmitting flags over FDL.
    Subsequently user issues

    • inform task TaskNo "XX" to transmit a single codeword, where XX is hexadecimal representation of the codeword
    • inform task TaskNo "XX*RepeatCount" to transmit the same codeword RepeatCount times,
      where XX is hexadecimal representation of the codeword. The RepeatCount determines the time duration of the same codeword being transmitted
    • inform task TaskNo "XX XXXX XXXX XX" to transmit an HDLC frame over FDL. XX is hexadecimal representation of the HDLC frame octets and must be in pairs. For example "11 22AB CD" is OK, while "1 1223344" is not. FCS (CRC) will be appended to the frame octets at the transmission time. Finally user should terminate the task to finish FDL transmission

For additional syntax download the sample script


Please Note: The XX in the Item No. refers to the hardware platform, listed at the bottom of the Buyer's Guide, which the software will be running on. Therefore, XX can either be ETA or EEA (Octal/Quad Boards), PTA or PEA (tProbe Units), UTA or UEA (USB Units), HUT or HUE (Universal Cards), and HDT or HDE (HD cards) depending upon the hardware.

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