M160 Internet Router Hardware Guide
Figure 89: Connecting Fiber-Optic Cable to a PIC
R
1239
Replacing a PCG
During normal operation, both PCGs generate a 125-MHz clock signal, but only
one is designated as the master. The modules and ASICs in the Packet Forwarding
Engine that use the clock signal to gate packet processing use only the signal from
the master PCG. For information about determining which PCG is the master, see
“Maintaining the PCGs” on page 135.
PCGs are hot-pluggable, as described in Field-Replaceable Units (FRUs) on page
4. Removal or failure of the backup PCG does not affect router function. If the
master PCG fails or is removed from the chassis, however, the Packet Forwarding
Engine resets so that the components start using the signal from the other PCG
(which becomes the master). Packet forwarding halts while there is no clock signal,
because the Packet Forwarding Engine does not accept incoming packets.
To replace a PCG, perform the following procedures:
Removing a PCG on page 176
Installing a PCG on page 178
Removing a PCG
To remove a PCG, follow this procedure (see Figure 90):
1.
Place an electrostatic bag or antistatic mat on a flat, stable surface.
2.
Attach an electrostatic discharge (ESD) grounding strap to your bare wrist and
connect the strap to one of the ESD points on the chassis. Make sure the router
is attached to a proper earth ground. For more information about ESD, see
“Preventing Electrostatic Discharge Damage” on page 226.
176
Replacing Packet Forwarding Engine Components
Содержание Internet Router M160
Страница 12: ...M160 Internet Router Hardware Guide xii Table of Contents ...
Страница 16: ...M160 Internet Router Hardware Guide xvi List of Figures ...
Страница 18: ...M160 Internet Router Hardware Guide xviii List of Tables ...
Страница 24: ...M160 Internet Router Hardware Guide xxiv Requesting Support ...
Страница 26: ...2 Product Overview ...
Страница 30: ...M160 Internet Router Hardware Guide 6 Safety Requirements Warnings and Guidelines ...
Страница 66: ...M160 Internet Router Hardware Guide 42 Cable Management System ...
Страница 80: ...M160 Internet Router Hardware Guide 56 Routing Engine Architecture ...
Страница 82: ...58 Initial Installation ...
Страница 104: ...M160 Internet Router Hardware Guide 80 Unpacking the Router ...
Страница 148: ...M160 Internet Router Hardware Guide 124 Configuring the JUNOS Internet Software ...
Страница 150: ...126 Hardware Maintenance Replacement and Troubleshooting Procedures ...
Страница 242: ...M160 Internet Router Hardware Guide 218 Troubleshooting the Power System ...
Страница 244: ...220 Appendixes ...
Страница 292: ...M160 Internet Router Hardware Guide 268 Packing Components for Shipment ...
Страница 301: ...Part 5 Index Index 277 ...
Страница 302: ...278 Index ...