Service Manual

253
6802800U74-AN
Chapter 6: Configuration and Testing
NOTICE:
Depending on the testbox equipment model, the delay parameter -d may vary and
should be adjusted accordingly.
Some testbox equipment can only generate T1 signal according to EN 300 394 (with
synchronization information in Frame 18), which can negatively impact BER
measurement results. If this is the case, it is recommended to perform measurements on
a single time slot by changing the TS parameter value -s to one of the following values:
• -s8
• -s4
• -s2
• -s1
In this way, the only TSs used are 4, 3, 2, or 1.
For details regarding different available parameters options, see the “peer_test_mode”
section in MTS Man Machine Interface Commands.
9 Type enable -orxch1 -dbr1 -son to enable the receiver branch under test.
This command should enable br1, br2, or br3 respectively depending on the receive branches
that you are testing.
10 Type sge -orx_all -soff to turn off the sys gain.
11 Measure RSSI for receive path 1, 2, and 3. Check that BER is 0%. Type ppr -orxch1 -a10
-r1
Step example:
Receiver Number
=
1
2
3
SGC Attenuation
=
26214
26214
26214
Sync Location
=
276
264
258
Sync. Amplitude
=
131070
131070
131070
Total Bits
=
2592
2592
2592
Bits in Error
=
0
0
0
BER (%)
=
0.0000000000
0.0000000000
0.0000000000
RSSI (dBm)
=
-36
-37
-36
12 For each receiver branch, calculate the difference between -40 dBm and measured RSSI level
using the following formula:
RX<receiver branch number> delta = -40-(-<RSSI (dBm) measured level>)
Step example:
RX1 delta : -40-(-36) = -4
RX2 delta: -40-(-37) = -3
RX3 delta: -40-(-36) = -4
13 Set the RSSI calibration values using the results from step 12 using the following command:
fcp -orxch1 -pcal_br<receiver number> -v<calculated calibration value>
Step example:
fcp -orxch1 -pcal_br1_hp -v-4
fcp -orxch1 -pcal_br2_hp -v-3
fcp -orxch1 -pcal_br3_hp -v-4
NOTICE: RSSI calibration is not operational before the BR is reset.