MOGlabs ARF021, Manual

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78
Chapter 9. Advanced table mode (XRF)
9.3 Initial and final states
As in simple table mode, when the
TABLE,ARM
command is used to
ready the table for execution, the output is enabled and amplifiers
switched on (if present). The state of the
RF
after arming is therefore
the same as the last table instruction that was run.
In simple table mode, the first instruction specified all three para-
meters, so the state at each step is well-defined and repeatable.
However, in parallel mode only one parameter is specified and the
other two may be undefined. It is strongly recommended that the
start and end of every table reset all parameters to known values,
as demonstrated in the listing below.
TABLE,CLEAR,1
TABLE,XPARAM,1,POW
# create table entry specifying a known start condition
TABLE,APPEND,1,80MHz,5dbm,45deg,976ns,OFF
# activate the update
TABLE,APPEND,1,POW,5dbm,16ns,UPD
#
−−
1us has elapsed up to here
−−
#
# ... other table mode entries ...
#
# add a final entry to reset rf state
TABLE,APPEND,80MHz,5dbm,45deg,1us
# activate the update, and turn off the rf
TABLE,APPEND,1,POW,-30dbm,UPD,OFF
Listing 9.4:
Setting initial and final states in parallel mode
The RF state at the last instruction is held after the table has finished
executing, which may involve the
RF
being on or off depending on
the desired application. If it is desired for the RF to be switched
off, then the amplitude should be set to zero on the final instruction
instead of using the OFF flag, as the RF output will be switched on
immediately following the next table rearm.
It is also possible to manually use the commands
FREQ
,
POW
and
PHASE
in advanced table mode to set the initial conditions
when the
table is not running
. Once the table has finished executing, the last