Toshiba STRATA DK14 Installation And Maintenance Manual page 669

Optional RBSS1A
UP
Two-circuit Subassembly
Figure 16-10 Location of RBSU Plug-on PCBs
Step 6: Install RBSU/RBSS PCBs into Cabinet
After setting the switches and jumpers and installing the plug-on PCBs as described in the
preceding paragraphs, the RBSU/RBSS PCBs can be installed in the appropriate cabinet slots.
Refer to RBSU/RBSS Capacity and Cabinet Slot Information on
RBSS is installed in the DK424 or DK424i cabinet or DK40i Expansion Unit, the status LEDs and
connecting jacks are positioned as shown in
Table 16-11 RBSU/RBSS LED Indications
LED
Circuit Busy
BSY On – Any B-channel is in use.
Off – B-channels are idle.
Timing Source
Blinking On/Off – The RBSU is extracting the clock from the BRI line and is the
Primary synchronization circuit for ISDN and T1.
TS
On – The RBSU is the secondary (backup) synchronization circuit for the ISDN
and T1.
Off – The RBSU is not used for ISDN or T1 synchronization.
Loss of Signal
LOS On – Clock timing cannot be detected from the line.
Off – Normal condition.
Frame Alignment Alarm
FS On – Frame alignment cannot be established.
Off – Frame alignment is established.
Strata DK I&M 6/00
RBSU
UP
2761
UP
R40S1A-CM V.1
R40S
Figure
Indication
RBSU/RBSS and TBSU Interface Units
REBS
(always install)
UP
UP
Optional PS-1 Power Supply
Figure 16-12. After the RBSU/
16-13.
ISDN Interfaces
UP
16-19