31
SHM-768K
Figure 5-1. BERT Using Loops.
Alternatively, the complete link can be tested when used opposite an
SHM-768K either with the PATT button pressed or with an external BERT
transmitting the same 511-bit pattern (according to V.52), as in Figure 5-2.
To activate the BERT, press the PATT button. If errors are encountered,
the ERROR LED will light (continuous errors) or blink (intermittent errors).
When PATT is pressed, the ERROR LED will light for a short time to confirm
that the ERROR LED is working.
NOTE
For correct operation of the BERT, the jumper CARR must be set to ON
or the RTS signal must be high.
When PATT is pressed, the external BERT is functionally disconnected.
PATT
DEPRESSED
XMT
RCV
ASM-45
ERROR
PATTERN
TESTER
PATTERN
GENERATOR
