Keysight CXG, EXG, and MXG X-Series Signal Generators Programming Guide 385
Creating and Downloading User–Data Files
Data Transfer Troubleshooting
Requirement for Continuous User File Data Transmission
“Integer Number of Timeslots” Requirement for Multiple–Timeslots
If a user file fills the data fields of more than one timeslot in a continuously
repeating framed transmission, the user file is restarted after the last timeslot
containing completely filled data fields. For example, if the user file contains
enough data to fill the data fields of 3.5 timeslots, the firmware loads 3
timeslots with data and restart the user file after the third timeslot. The last 0.5
timeslot worth of data is never modulated.
To solve this problem, add or subtract bits from the user file until it completely
fills an integer number of timeslots
“Multiple–of–8–Bits” Requirement
For downloads to bit and binary memory, user file data must be downloaded in
multiples of 8 bits (bytes), since SCPI specifies data in bytes. Therefore, if the
original data pattern’s length is not a multiple of 8, you need to:
— add bits to complete the ASCII character
— replicate the data pattern to generate a continuously repeating pattern with
no discontinuity
— truncate the excess bits
Using Externally Generated, Real–Time Data for Large Files
When the data fields must be continuous data streams, and the size of the data
exceeds the available PRAM, real–time data and synchronization can be
supplied by an external data source to the front panel DATA, DATA CLOCK, and
SYMBOL SYNC connectors. This data can be continuously transmitted, or can
be framed by supplying a data–synchronous burst pulse to the EXT1 INPUT
connector on the front panel. Additionally, the external data can be
multiplexed into internally generated framing
PRAM Download Problems
The “multiple–of–8–bits” data length requirement is in addition to the
requirement of completely filling the data field of an integer number of
timeslots.
Table 6-15
PRAM Download – Symptoms and Causes
Symptom
Possible Cause
The transmitted pattern is interspersed
with random, unwanted data.
Pattern reset bit not set.
Insure that the pattern reset bit (bit 7, value 128) is set on the last byte of your
downloaded data.
Summary of Contents for X-Series
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