Zte ZXG10 BS21, Руководство по обслуживанию

Страница: 85 / 249

Chapter 3 - Routine Maintenance
Confidential and Proprietary Information of ZTE CORPORATION 71
Calibrating Clock
[ Instruments and meters ]
A cymometer and a laptop installed with LMT software
[ Test procedure ]
1. Set base station to work at the internal synchronization mode at OMCR.
2. The cymometer is connected with the 13 M clock test interface on the
front panel of the BS21 rack.
3. The serial port of the notebook is connected with the external testing
port (ETP) of the CMM module.
4. Start LMT in the notebook and click "CKU Calibrate" in the menu to
enter the correction interface of CKU as shown in Figure 63.
F
I G U R E
6 3 C K U C
O R R E C T I O N
5. Press “Start” to originate communication with the foreground. “Start”
is valid when the program is started. Other buttons are invalid. “Start”
becomes invalid when pressing “Start” to originate communication with
the foreground, and other buttons like “Calibrate” become valid.
6. The current CKU values are displayed in the CKU Calibration interface,
including the DAC value and the voltage. Calibrate the DAC value in
the Calibration box. You can enter a DAC value manually, or click the
up/down arrows to the right of the DAC value box to adjust the value.
The step length of each increase or decrease in the DAC value is
determined by the step value. Three options are available: 1, 3 and 10.