T640 T Series Control Boards (T-CBs) Description
This chassis supports up to two T-CBs. The Routing Engine requires an adjacent T-CB to provide control and monitoring functions for the router (see Figure 1). These functions include determining Routing Engine mastership, controlling power and reset for the other router components, monitoring and controlling fan speed, and monitoring system status.
You can install up to two T-CBs in the router. Control boards install into the upper rear of the chassis in the slots labeled CB0 and CB1 (referred to as CB-0 and CB-1, top to bottom). If two T-CBs are installed, one functions as the master and the other as its backup. If the master fails or is removed, the backup restarts and becomes the master.
Each T-CB requires a Routing Engine to be installed in the adjacent slot. CB0 installs above RE0, and CB1 installs below RE1. T-CBs cannot function if a Routing Engine is not present in the adjacent slot.
If the host system is redundant, the backup T-CB is hot-removable and hot-insertable, but the master T-CB is hot-pluggable. A T-CB that is not redundant is hot-pluggable.
Figure 1: T-CB
 | Note: The T-CB requires Junos OS Release 7.0 or later. |
Each T-CB consists of the following components:
- 100-MB Ethernet switch for intermodule communication.
- PCI bus to the Routing Engines.
- Processor subsystem (SPMB).
- Three LEDs, located on the T-CB faceplate, indicate its status.
- The T-CB online/offline button, located on the faceplate. This button is nonfunctional.
- Two configuration switches, located on the faceplate:
- For a standalone T640 router, the M/S and CHASSIS ID configuration switches must always be set to S and 0.
- For T640 routers connected to a TX Matrix platform, the M/S and CHASSIS ID configuration switches must always be set to M and the chassis identifier (ID) of the router. In this case, both T-CBs must have the same chassis ID. For more information, see the TX Matrix Router Hardware Guide.
- Two RJ-45 ports labeled AUX and CIP on
the T-CB faceplate.
- For a standalone T640 router, these ports are not used.
- For T640 routers connected to a TX Matrix platform, only the CIP port is used. For more information, see the TX Matrix Router Hardware Guide.
