DAZZLER
TM
system manual Part I : installation & operation
8.4
or when the
aux
signal is LOW. The indicator follows the signal at the
aux
input.
8.2.6
RF ON indicator
This is the rightmost LED, just above the RF output power SMA plug. This indicator is lit
when the RF generator board sees a non zero signal being output in the RF cycle. This is not
an indication of power, it just means RF cycles are produced with non zero samples.
8.3
Logic levels & signals
The logic signals of the RF generator are interfaced with special cable drivers integrated cir-
cuits
. Logic levels are TTL: LOW is below 0.6 V, HI is above 3.3 V. Refer to the datasheets for
more details. Some newer generators equipped with RF boards V5.6 are fitted with an internal
jumper selecting between 5V TTL and 3.3V TTL.
High speed logic signals must be properly terminated: see
for the
trigger
and
aux
signals Dazzler input.
is full of practical advice to avoid unstabilities due
to EMI.
8.4
Input signals
8.4.1
Input signal
trigger
This signal is essential to the successful operation of the Dazzler with the laser system. Please
refer to
for more details. The following actions are started by the
trigger
:
•
the rising edge of the
trigger
pulse starts a retriggerable multivibrator
trigina
, sub-
sequent rising edges occuring while
trigina
is high are blocked but restart a blocking
period (only for
trigger
pulses applied to the BNC socket).
•
the rising edge of
trigina
starts the delay period,
•
the internal delayed trigger
gentrig
starts the RF cycle, it is blocked if falling in the
protection period
protectp
. The protection period is defined by the waveform being
displayed. It prevents to start another waveform if the average thermal power delivered
to the crystal would exceed the safe limit.
•
note that
trigina
comes from an unsampled analog circuit.
4
The following chips have been used: 74AC14B, 74LVC14D, 74AHC1G14, 74AC14D.
V3.00 - 8
th
April 2019
