Rohde & Schwarz SME02 - Page 169

SME Digital Modulation
1038.6002.02 2.123 E-13
SCI BASE FRAME
System configuration information (SCI) frames are transmitted
within each cycle of 128 frames. Their positions within the cycle is
calculated according to
INDEX = SCI BASE FRAME + 2
SCI COLLAPSE MASK
* i for all i, until INDEX exceeds
127
SCI BASE FRAME and SCI COLLAPSE MASK are transmitted to
the receiver in the respective block information words.
IEC-bus command: SOUR:REFL25:SI:SCIBase 0
SCI COLLAPSE MASK
See explanation under SCI BASE FRAME.
IEC-bus command: SOUR:REFL25:SI:SCICollapse 7
-- BIT ERRORS --
The SME allows for providing a 32-bit word of the transferred
message with bit errors for test purposes. The following
parameters specify the bits to be falsified and the position of the
erroneous word within a frame. The bit errors are incorporated
before the individual blocks are subjected to interleaving (see
ReFLEX25 documentation).
ERROR BIT MASK
Input of the bits to be falsified. The set decimal number is
converted internally into a 32-bit binary number. This binary
number is XORed with the original message word. Each bit of the
ERROR BIT MASK set to 1 causes an inversion of the respective
bit in the transmitted word.
IEC-bus command: SOUR:REFL25:ERR:MASK 0
POSITION OF ERRONEOUS
WORD
Indicates the position of the erroneous word. The erroneous word
appears in each frame. Counting starts with the first word of block
0 of each frame, i.e. immediately
after the sync partition; the sync
partition cannot be falsified. Values from 0 to 351 can be set.
Depending on the modulation, a frame (without sync partition)
consists of 88, 176 or 352 words. If an excessive value is entered
for POSITION OF ERRONEOUS WORD for the set modulation,
no bit errors are produced.
IEC-bus command: SOUR:REFL25:ERR:WORD 0
-- MESSAGE GENERATION --
The SME always sends complete cycles consisting of up to 128
frames. The parameters of this section specify the frame
contents.