following test 1 of line port reference in section 3, the dte port can be tested.

    4.1 dut installation and test environment

    in addition to the test environment of test 1 of section 3, add the v.35 test set. plug the v.35 cable from the tester to the dte port of the dut. see figure 2.

    4.2 power up

    as in test of section 3.

    4.3 dut configuration

    in addition to the configuration setup of test 1 of section 3, the following dte configuration is needed.

    4.3.1 additional parameters for dte port

    speed=64k

    channel=ch-b1

    clock=normal

    data=normal

    rts=permanent

    ttm=off

    interface=v.35

    4.3.2 setup using front panel lcd and keys

    use the same procedure as in test 1.

    4.3.3 setup using termianl

    with the terminal connected and displaying the main menu, press the s key for system setup.(press o if the right hand half of the screen is blank. the password is"loop".) then use the arrow key to move the cursor to the parameters to be changed and use the tab key to roll to the desired parameter setting. when done, press esc key to return th the main menu .

    4.4 bit error test

    after configuration setup , a"bit error test" is performed to verify proper operation.

    the test can be initialed either from the front panel lcd and keypad or attached vt100 terminal.

    4.4.1 test using front panel lcd and keys

    (a) from the main menu , showing diagnostics is displayed. press enter.

    (b) nt mode one selects"near loopback" and press enter. press right or left arrow key until" payload" is displayed. press enter.

    4.4.2 test using terminal

    with the terminal connected (lt) and displaying the main menu, press the"t" key for loopback tests. then use the arrow key to move the cursor to remote loopback(2b+d). press enter.

    to test the dte port, set up the configuration of the tester.

    (a) v.35: dte emulation

    (b) clock source: interface (i.e. the clock source is supplied from the dut).

    (c) execute the bit error test by sending test pattern from tester and observe the bit error count.

    4.4.3 test result

    test duration should be at least 2 minutes.

    if the bit error = 0, then the dte port and related functions are working. the dut is working. else they failed. on the fireberd 6000, the display is"bit errs 0".