Siemens HiPath 3000 Operating Instruction page 162

Step by Step
Please detach and
attach cord to handset
Test Passed!
162
Remove the cord and re-insert it. An acknowledgement
tone sounds both when the cord is removed and when
it is replaced.
Shown on display if the test was successful. If not, the
entire function test is cancelled and "Test Failed!" is
displayed. Start the startup procedure again.
Note:
If the function test fails repeatedly, shut down
the handset immediately and send it to the
manufacturer.
When the function test has ended, the handset
automatically calls the alarm server and passes on the
test result.
Look out for display and voice output from the alarm
server.