Replacing Connections to M120 Routing Engine Interface Ports

The ports on the craft interface connect the Routing Engine to external management devices (see Figure 1).

Figure 1: M120 Routing Engine Interface Ports and Alarm Relay Contacts

To replace the cables that connect to the ports:

Replacing the Management Ethernet Cable on the M120 Routing Engine

For cable specifications, see Routing Engine Interface Cable and Wire Specifications for the M120 Router. To replace the management Ethernet Cable:

1. Press the tab on the connector and pull the connector straight out of the ETHERNET port. Figure 2 shows the connector.
2. Disconnect the cable from the network device.
3. Plug one end of the replacement cable into the appropriate ETHERNET port. Figure 3 shows the external device ports on the craft interface. The ports labeled 0 connect to the Routing Engine in the left Routing Engine slot (RE0), and the ports labeled 1 connect to the Routing Engine in the right Routing Engine slot (RE1).
4. Plug the other end of the cable into the network device.

Figure 2: M120 Ethernet Cable Connectors

Figure 3: M120 Routing Engine Interface Ports and Alarm Relay Contacts

Replacing the Console or Auxiliary Cable on the M120 Routing Engine

To use a system console to configure and manage the Routing Engine, connect it to the appropriate CONSOLE port on the craft interface. To use a laptop, modem, or other auxiliary device, connect it to the appropriate AUX port on the craft interface. Both ports accept a cable with an RJ-45 connector. One RJ-45/DB-9 cable is provided with the router. To connect a device to the other port, you must supply another cable. For cable specifications, see Routing Engine Interface Cable and Wire Specifications for the M120 Router.

To connect a management console or auxiliary device:

1. Plug one end of the replacement cable into the appropriate CONSOLE or AUX port. Figure 4 shows the external device ports on the craft interface. The ports labeled 0 connect to the Routing Engine in the left Routing Engine slot (RE0), and the ports labeled 1 connect to the Routing Engine in the right Routing Engine slot (RE1).
2. Plug the other end of the cable into the device's serial port.

Figure 4: M120 Routing Engine Interface Ports and Alarm Relay Contacts

Replacing Alarm Relay Wires on the M120 Craft Interface

To connect the router to external alarm-reporting devices, attach wires to the RED and YELLOW relay contacts on the craft interface. A system condition that triggers the red or yellow alarm LED on the craft interface also activates the corresponding alarm relay contact.

The terminal blocks that plug into the alarm relay contacts are supplied with the router. They accept wire of any gauge between 28-AWG and 14-AWG (0.08 and 2.08 mm²), which is not provided. Use the wire gauge appropriate for the external device you are connecting.

To replace the wires connecting to an alarm-reporting device (see Figure 5):

1. Disconnect the existing wire at the external device.
2. Prepare the required length of replacement wire with gauge between 28-AWG and 14-AWG (0.08 and 2.08 mm²).
3. Using a 2.5-mm flat-blade screwdriver, loosen the small screws on the face of the terminal block and remove the block from the relay contact.
4. Using the 2.5-mm flat-blade screwdriver, loosen the small screws on the side of the terminal block. Remove existing wires from the slots in the front of the block and insert replacement wires. Tighten the screws to secure the wire.
5. Plug the terminal block into the relay contact and use a 2.5-mm flat-blade screwdriver to tighten the screws on the face of the block.
6. Attach the other end of the wires to the external device.

Figure 5: M120 Routing Engine Interface Ports and Alarm Relay Contacts