Digital Modulation SME
1038.6002.02 2.130 E-13
----BIT ERRORS---
The SME allows for providing a 32-bit-word of the transferred
message with bit errors for test purposes. The parameters of this
section specify the erroneous bits and their positions.
ERROR BIT MASK
Entry of the erroneous bits in a 32-bit field. The transmitted
decimal number (0...4294967295) is converted internally into a
32-bit binary number and thus defines the 32 bits. These bits are
XORed with the word of the message which is to be falsified and
thus determine which bits of this word are to be transmitted
correctly or incorrectly.
IEC-bus command :SOUR:POCS:ERR:MASK 0
POSITION OF ERRONEOUS
WORD
Entry value of the position of the word to be falsified in the batch.
Values from 0 to 16 are valid. The value 0 denotes the
synchronization word.
IEC-bus command :SOUR:POCS:ERR:WORD 0
--- MESSAGE GENERATION ---
The parameters of this section determine which types of data
(POCSAG message, POCSAG filler data) are sent at what time.
FILL-BATCHES BEFORE MESSAGE
Input value for the number of filler batches emitted prior to the
actual message.
This allows, e. g., to create a test message according to FTZ
171TR1, appendix 1, section 3.2.2, where the message must
appear in the 7
th
batch
IEC-bus command :SOUR:POCS:LBAT 0
TIME SLICE
Input value of the length of the time slice.
Possible values are: 2 to 120 sec.
A preamble of 576 bits is sent at the beginning of every time slice,
followed by the number of filler batches set under FILL-BATCHES
BEFORE MESSAGE. Each batch has the length of 544 bits.
Depending on the settings under MODE, zero, one or two
message batches follow. Then an unmodulated signal is sent up
to the end of the time slice.
Due to the fact that only complete code word groups are sent, it is
possible that, depending on the set bit rate, the actual length of
the time slice slightly differs from the set length of the time slice.
IEC-bus command :SOUR:POCS:TSL 10
RECALCULATE Ð
Triggers a recalculation of the generated POCSAG telegram.
The telegram which is to be sent is recalculated using the set
values. As a result of this function, a change in the settings also
becomes effective in the generated signal.
IEC-bus command :SOUR:POCS:STAT OFF;STAT ON
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