Verilink PRISM 4051 (34-00253.2) Product Manual - Manual (Page 24)

18 C HAPTER 3: O PERATION
4 RTS: This green indicator lights when the request to send signal is active.
5 DTR: This green indicator lights when the data terminal ready signal is active.
Test Controls
and Indicators
6 Test Switch: This switch (FAR /LOC) is used for local testing. Refer to section
Front Panel Testing in this chapter for more information.
7 Activity Indicators: These two small, recessed indicators show supervisory and
network manager port transmission activity.
8 SUPV: The supervisory jack provides direct terminal access to control and
monitor the 4051. Refer to section Supervisory Port on page 20 for more
information.
Alarm Controls
and Indicators
9 LOS: This indicator lights with a loss of signal from the DDS network.
10 OOF: This indicator shows that the unit detects an out of frame condition or OOF
codes are received.
11 LOOP: This indicator lights continuously when the network interface is in any
loopback.
12 BERT: This indicator shows that a 511-bit BERT is in progress.
13 ERR: This indicator shows when BERT pattern errors are detected.
Front Panel
Testing The previous section gave a brief description of each front panel control and
indicator. This section explains the front panel test functions. Testing may also be
performed using software control from the 8100A Site Controller or the Terminal
Interface program (refer to chapter Terminal Operation).
Test Switch The test switch, labeled FAR/LOC, is used for local testing. When in the FAR
position, the 4051 sends five seconds of the V.54 loop pattern, then switches to the
511 pattern. When transmitting a test pattern, the BERT indicator stays On. The
ERR indicator lights for one second when a bit error or sync loss on the returned
data is detected.