Specifications

Programming Guide 3-37
ESG Family Signal Generators Remote Data Transfer
Data Transfer Troubleshooting
The first row where both columns C and D are integers (the shaded row at the bottom of
the table) is the minimum number of repetitions required to transmit the user file without
discontinuity. In this example, in order to correctly generate the modified PN9 and
download it to a user file, the user file must contain 456 repetitions of the 511-bit pattern.
233,016 total bits will be downloaded to the signal generator, for a total of 29,127
characters.
“Pattern RAM Memory Space” Requirement It is possible to exhaust the available
PRAM with a large, continuous user file transmitted across a large number of frames.
In the previous example, selecting the 233,016-bit user file as the data source for the
GSM Normal timeslot will cause the firmware to compute 2,044 frames of data, filling
2,555,000 bytes of PRAM space. Option UN9 (8 Mbyte pattern RAM) is required for this
configuration. Trying to load this data on an Option UN8 (1 Mbyte pattern RAM) signal
generator will cause an error, because there is not enough PRAM to hold the required data.
If PN11 was used instead of PN9, 456 repetitions of the data pattern would require a
933,432-bit user file, requiring 8,188 frames and 10,235,000 bytes of PRAM. Because the
size of this data exceeds the limits of Option UN9 (8 Mbyte PRAM), you would need to
supply a file this size via the external DATA connector.
Using Externally-Generated, Real-Time Data for Large Files If the data fields
absolutely 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 the internally-generated framing.
NOTE This chapter does not cover externally-generated real-time data. See the
ESG Family Signal Generator User’s Guide for details and timing diagrams.
8 4,088 511 35.86 44,824.56
9 4,599 574.88 40.34 50,427.63
... ... ... ... ...
455 232,505 29,063.13 2,039.52 2,549,396.92
456 233.016 29,127 2,044 2,555,000
Table 3-5 Data Pattern Repetitions for Continuous Data Stream (Continued)
AB C D E
Number
of reps
Data
Pattern
Length ×
Repetitions
Number of
Characters
(B ÷ 8)
Number of frames needed to
end on a timeslot boundary
(B ÷ timeslot data field size)
Total PRAM required
(D × number of
bits-per-frame)