User's Manual

Doc. No.
Rev.
Date
DRAFT
1.01
2012-01-27
Damm Cellular Systems A/S, Denmark
TetraFlex
®
7.5 Manual - BS421 Configuration
TetraFlex® 7.5 Manual 2-76
TR11 SEC IN
TR12 SEC IN
SEC IN 1 (BSC2)
SEC IN 2 (BSC1)
Figure 2-20: 1 second Sync indicators
NOTE: HW changes to SB421 interconnection board and TE2 and TR4 required
2.6.4.4.1 GPS setup commands
To enable GPS synchronization execute the following TetraOM commands: 72/IN/G/+
2.6.4.5 BS421 manual frequency adjustment procedure
If the BS is operating without GPS sync. (Free run) the reference oscillator has to be checked
and adjusted one time a year.
Measure the BS421 transmitter frequency, the transmitter can be switch to CW mode for
easier measurement.
Commands :
01+ ;Local blocking
02/- ;Test mode
15/CW ;CW modulation
10+ ;Start transmitter
Commands to adjust the reference oscillator:
31 ;Display Sync status, note the DAC output value (OCXO Free Run value)
31/SET/nn.nnn ;Set the OCXO Free Run value, range from 00.000% to 99.999%
31/SAVE ;Save the OCXO Free Run value to flash
A change of 1% will give a frequency change about 0.1PPM