Programming instructions

151
Upgrades and FRUs
Install Digital Service Unit FRUs
The DSU has the following Field Replaceable Units (FRUs):
• Circuit card (page 143)
• BRI card (page 152)
• BRI interface assembly (page 153)
• Formatter cards (CEPT, DS1) (page 154)
• PRI card (page 154)
• Peripheral resource card (page 156)
• FIM (page 157)
• R2 card (page 158)
Removing/Replacing the Front Panel
See “Removing/Replacing the Front Panel of a Peripheral Cabinet or
DSU” on page 142.
Powering Down the DSU Unit
To power down the DSU:
1. Set the power switch on the rear of the unit to ‘0’ (OFF).
2. Unplug the external power cord at the rear of the unit.
Powering Up the DSU Unit
To power up the DSU:
1. Connect the external power cord at the rear of the unit.
2. Set the power switch on the rear of the unit to "I" (ON).
Replacing Circuit Cards
See “Replacing Circuit Cards” on page 143.
Tip: The CX and CXi controllers do not support Digital Service Units.