CANOGA PERKINS 2240 Fiber Optic Modem - Manual (Page 21)

2240 Fiber Optic Modem
21
2.1.5 2202 Modem Shelf Installation
The 2202 Modem Shelf is mounted in an equipment rack. Two 2200 Series standalone
modems may be installed in the 2202, side-by-side on the shelf. Refer to the 2202
Modem Shelf User Manual for more information about installation.
2.1.6 Custom Oscillator Installation
The third oscillator on the main 2240 board can be installed or changed to allow the use
of Group 4 Internal Clock Rates.
Once the board is accessed, notice the four-pin socket located near the two standard
oscillators (see Figure 2-2). Ensure that the oscillator pins are straight and that the
modem is not powered up. Insert the oscillator in the same orientation as the two
standard oscillators, then reinstall the modem.
NC
NO
O
N
O
FF
O
N
O
FF RLY
ALM+
ALM-
1
STANDARD
OSCILLATORS
CUSTOM
OSCILLATOR
SOCKET
Figure 2-2.
Location of
Oscillators