PairGain HiGain HLU-319 Manual page 41

150-319-142-01
Some Intelligent Repeater (IR) test sets do not count frame
errors as bit errors when the test pattern is framed and the
HLU-319 List 4B is set to the AUTO framing mode. To improve
compatibility with those test sets, the HLU-319 List 4B generates
232 (NLOC) ID bit errors. The HLU-319 List 4B can indicate one
more or one less bit error, depending on the test set type and the
number of frame bits contained in the block of errored bits. To
avoid this uncertainty, PairGain recommends sending the IR
commands unframed.
The HLU-319 List 4B is now in Logic Loopback. The Loopback
Time-out option is user settable to:
•
NONE (0 minutes)
•
20 minutes
•
60 minutes
•
120 minutes
on the System Settings menu (Loopback Timeout option).
The loopback time option determines the duration of a loopback unless
it is overridden by the Time-out Override command or a loop-down
command is sent. If the Time-out Override code 1101 0101 1101 0110
(D5D6) is received, the activation sequence is repeated and the automatic
timed expiration is inhibited. If this Time-out Override is sent, loop down
the HLU-319 List 4B by:
•
issuing the IR (Intelligent Repeater) LPDN (loop-down) code 1001
0011 1001 0011 (9393) or
•
issuing the NI LPDN and Disarm code 11100
The automatic time-out timer is restored during subsequent loopback
sessions.
5 Once the test is complete, do one of the following:
•
If the system is to loopdown but remain ARMED, send the IR
(Intelligent Repeater) LPDN code (universal loopdown).
•
If all the equipment is to loopdown, disarmed and returned to normal
operation, send the disarm code 11100.
HLU-319 List 4B
December 22, 1997
PairGain Engineering - Plant Series
Revision 01
35