User Manual

ADCP-75-192 • Issue 1 • December 2005 • Section 2: Description
Page 2-22
 2005, ADC Telecommunications, Inc.
Table 2-13. RSC User Interface, continued
REF
No.
USER INTERFACE
DESIGNATION
DEVICE FUNCTIONAL DESCRIPTION
3 Hot Swap LED Single-colored LED
(Blue)
Status indicator turns blue when board can be hot swap
extracted.
4 Power LED Single-colored LED
(Green)
Status indicator turns green when module has power.
5 Fault LED Single-colored LED
(Red)
Status indicator turns red when module has failed.
6.5 Hub Reference Module (HRM)
The Hub Reference Module (HRM) is used to:
• Provide clock referencing (RF and digital) to the cPCI chassis.
• Interface to GPS antenna.
• Provide 1PPS, derived from GPS, to Digital Chassis for delay management.
For every Hubmaster CPU there is only one Master HRM. This unit is the interface to the GPS
antenna. The Hub rack managing this Master HRM must be setup to monitor the GPS antenna.
Therefore, only the Master HRM must be monitored for “antenna feedline” fault status. All
other HRMs must be daisy chained to this GPS input. Starting with the Master HRM, connect
“GPS AUX” of the donor HRM to “GPS IN” of the next HRM in line using an SMA coax
cable.
For simulcasting, redundancy, and other functions, HRMs must also share the same clock
reference across multiple racks. This is accomplished by daisy-chaining the reference via RJ-
45 ports on the back of the unit (see figure 2-21). Starting with “9.6 MHz” RJ-45 port “B” of
the Hubmaster HRM, connect a crossover CAT-5 from port B of each donor HRM to port A of
the next HRM in line. Port B will remain open on the last HRM in the chain. Be sure to daisy
chain HRMs prior to powering them on or connecting them to I2C.
The HRM front panel is shown in Figure 2-20. The references for the HRM front panel are
shown in Table 2-14. The HRM rear panel is shown in Figure 2-21. The references for the
HRM rear panel are shown in Table 2-15.