DAZZLER
TM
system manual Part I : installation & operation 5.7
5.7 Warnings
Two other conditions cause the ”poll message” to become red and bold, as shown further.
Contrarily to alarms, these warnings do not signal impending damage to the Dazzler
TM
system
but that conditions are not correct (e.g. missed triggers due to delay). They disappear when
the cause is removed: there is no storage of temporary conditions nor any acknowledgment.
5.7.1 Missed triggers due to timing
Figure 5.22: missed triggers due to timing
This warning appears when triggers are ignored because they occur 1) during the delay period,
2) during the copy operation between different memories (sequences, aux selection ...), 3)
delayed triggers during gate. This warning is disabled for generators operating in the High
Repetition Rate mode (see section 4.3.5).
5.7.2 Missed triggers due to power
Figure 5.23: missed triggers due to power
This warning occurs when the average power to be delivered to the crystal would exceed the
crystal damage threshold. The Dazzler program prevents such a situation to happen by pre-
venting loading or switching waveforms as appropriate. This may happen after a waveform
is loaded and the trigger frequency is increased. In order to protect the crystal, triggers are
ignored during a protection period, computed to limit the average power.
5.7.3 Missed triggers unreported
The Dazzler RF Generator is used to generate an analog signal which is sent to the crystal
transducer to generate the appropriate acoustic pulse. This signal is generated by a Digital-to-
Analog (DAC) converter, which takes its input data from a dedicated memory buffer. When
one needs to update the shaping parameters of the Dazzler, the content of this buffer must be
overwritten. While the buffer content is being updated, it cannot send any data to the DAC,
hence the RF generation is stopped temporarily. If a trigger occurs during the time window
when the buffer content is being modified, the trigger is ignored, without any notification to
the control computer.
This generally occurs each time the user applies new shaping parameters to the Dazzler, in-
cluding when (but not limited to) :
V3.00 - 8
th
April 2019 (ContentsTable) (FiguresTable) 58/94
To Next Page
Loading...