Test Procedure SME
1038.6002.02 5.42 E-13
5.2.40 Memory Extension (Option SME-B12)
Note: To ensure a proper functioning of the memory extension (XMEM) the modification status of the
DM coder has to be at least VAR.2/REV.4. Menu UTILITIES-DIAG-CONFIG offers access to
indication of module modification status.
The read/write function via the IEC/IEEE bus and the interplay between the XMEM and the DM coder
during GFSK modulation (high bit rate) are first checked followed by checks of the dibit synchronization
for QPSK and external triggering.
5.2.40.1 Read/Write Check via the IEC/IEEE Bus
Measurement
Read in/read out
À Call up digital modulation GFSK via the IEC/IEEE bus on the SME
and activate memory extension (in R&S BASIC):
IEC OUT 28, ":DM:TYPE GFSK;STAT ON;SOUR DATA"
IEC OUT 28, ":SOUR:DM:DATA:SEL ’XMEM’"
À Read in first sequence into memory extension:
IEC OUT 28, ":DM:DATA:XMEM:START 88;LENG 3"
IEC OUT 28, ":SOUR:DM:DATA:DATA 1,0,1"
À Read in the three remaining sequences analogously.
À Read out sequences and compare with those sent:
IEC OUT 28, ":DM:DATA:XMEM:START 88;LENG 3"
IEC OUT 28, ":SOUR:DM:DATA:DATA?"
IEC IN 28, "SEQUENCE$": PRINT SEQUENCE$
The sequences read in have to correspond to the sequences read
out.
Recommended bit pattern
No. Sequence Sequence length
(LENGTH)
Start address
(START ADDRESS)
1 101 3 88
2 01010101011010 14 74
3 011101100101011 15 59
4 110011010001010
1
16 43
Measurement
Interplay between
XMEM and DM coder
After completion of this test XMEM is set so that the fourth sequence
is cyclically repeated and GFSK-modulated, and appears at the RF
output.
À Check the spectrum at the RF output according to the following
table. The levels refer to the carrier level with the modulation
switched off:
Offset frequency / 72 kHz
0 -2-6-8 2 4 6 8
Level/ dB ±3 dB
-12.3 -11.0 -16.4 -24.0 -18.4 -12.2 -25.2 -24.0
Measurement
Battery back-up
À The unit has to be switched off for at least 10 seconds and then to
be switched on again.
The above-mentioned spectrum has to be measured.
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