User Manual

CSM System Time/GPS and HSO Verification – continued

3-48 1X SC4812T–MC BTS Optimization/ATP 5/21/04

DRAFT

Table 3-20: GPS Initialization/Verification

Step Action

10 Observe the following typical response if the CSM is warmed up.

c:17486 off: –11, 3, 6 TK SRC:0 S0: 3 S1:–2013175,–2013175

c:17470 off: –11, 1, 6 TK SRC:0 S0: 1 S1:–2013175,–2013175

c:17486 off: –11, 3, 6 TK SRC:0 S0: 3 S1:–2013175,–2013175

c:17470 off: –11, 1, 6 TK SRC:0 S0: 1 S1:–2013175,–2013175

11 Verify the following GPS information (underlined text above, from left to right):

– Lower limit offset from tracked source variable is not less than –60 (equates to 3µs limit).

– Upper limit offset from tracked source variable is not more than +60 (equates to 3µs limit).

– TK SRC: 0 is selected, where SRC 0 = GPS.

12 Enter the following commands at the CSM> prompt to exit the debug mode display.

debug dpllp

HSO Initialization/Verification

The HSO module is a full–size card that resides in the C–CCP Shelf.

This completely self contained high stability 10 MHz oscillator

interfaces with the CSM via a serial communications link. The CSM

handles the overall configuration and status monitoring functions of the

HSO. In the event of GPS failure, the HSO is capable of maintaining

synchronization initially established by the GPS reference signal for a

limited time.

The HSO is typically installed in those geographical areas not covered

by the LORAN–C system and provides the following major functions:

S Reference oscillator temperature and phase lock monitor circuitry

S Generates a highly stable 10 MHz sine wave.

S Reference divider circuitry converts 10 MHz sine wave to 10 MHz

TTL signal, which is divided to provide a 1 PPS strobe to the CSM.

Prerequisites

S The LMF is not logged into the BTS.

S The COM1 port is connected to the MMI port of the primary CSM via

a null modem board.

S The primary CSM and the HSO (if equipped) have warmed up for 15

minutes.

If the BTS is equipped with an HSO, follow the procedure in Table 3-21

to configure the HSO.