Installing Cables. Procedures in Upward Cabling Mode. Installing STM-1 Cables. Procedures in Downward Cabling Mode, страница 9

Overview	This section tells you the procedures and precautions for installing and routing the external synchronization timing cable. The OptiX OSN 9500 has two G.703 input interfaces and two G.703 output interfaces at the rate of 2048 kHz or 2048 kbit/s. Their impedance is 75 W. If the clock interface impedance of the client is 120 W, 120/75 W clock transit cable is needed.
Prerequisites	n Check the construction condition The clock input/output equipment in the equipment room has been installed, with interfaces reserved for use in this installation. n Check the cabling route Work out the length of the required external synchronization timing cable according to the cabling route, as specified in the construction documents, between the cabinet and the clock input/output equipment in the equipment room. n Check installation materials Installation materials are complete. n Fill in cable labels Before cabling, you must fill in the cable labels according to “Appendix D Engineering Labels for Cables”.
Installation materials	n 75 W external synchronization timing cable n 120/75 W clock transit cable (optional) Figure 7-18 shows the outer views of the external synchronization timing cable and 120/75 W clock transit cable. n Labels for the external synchronization timing cables
Positions for cable interfaces	The external synchronization timing cables connect to the interfaces on the clock interface board (JSTI) of the OptiX OSN 9500, as shown in Figure 7-19.

1. External synchronization timing cables	2. 120/75 W clock transit cable (1 channel)
3. 120/75 W clock transit cable (2 channels)

Figure 7-18 External synchronization timing cable and clock transit cable

1. External clock input interface 1	2. Clock output interface 1
3. External clock input interface 2	4. Clock output interface 2

Figure 7-19 Positions of clock interfaces

7.4.1 Procedures in Upward Cabling Mode

Step	Operation
1	Before installing the cable, attach temporary marks to its both ends for distinguishing.
2	Connect the connectors of the external synchronization timing cables to the clock interfaces on JSTI.
3	Wire the external synchronization timing cables on the left in the subrack cabling trough below JSTI and lead them out. Route them upward along the post and then route them to pass through the cabling hole for signal cables on the top of the cabinet, as shown in Figure 7-20.
4	Bind the external synchronization timing cables properly, as shown in Figure 7-20.
5	Remove the temporary marks and attach the cable labels 2 cm away from the connectors at the two ends. In doing so, refer to section 7.2 “Installing STM-1 Cable”.

1. External synchronization timing cables

2. Cabling hole for signal cables

3. Subrack cabling trough

4. Post

Figure 7-20 Wire the external synchronization timing cable in upward cabling mode

7.4.2 Procedures in Downward Cabling Mode

Step	Operation
1	Before installing the cable, attach temporary marks to its both ends for distinguishing.
2	Connect the connectors of the external synchronization timing cables to the clock interfaces on JSTI.
3	Wire the external synchronization timing cables on the left in the subrack cabling trough below JSTI and lead them out. Route them downward along the post and then route them to pass through the cabling hole for signal cables at the bottom of the cabinet, as shown in Figure 7-21.
4	Bind the external synchronization timing cables properly, as shown in Figure 7-21.
5	Remove the temporary marks and attach the cable labels 2 cm away from the connectors at the two ends. In doing so, refer to section 7.2 “Installing STM-1 Cable”.

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