5-8
5 Pulse Generator Concepts and Operation
•
Burst Mode
System Timer Functions
The System Timer functions as a non-retriggerable, multi-vibrator T
0
pulse
generator in ‘Burst’
mode
. This means that once started the timer will
produce pulses continuously at the specified
rate
until the highest channel
burst count
is reached. Before pulses can be generated, the timer must
be armed and then receive a System Start pulse. Arming the counter is
done by pressing the
RUN/STOP
key. With external trigger disabled, the
RUN/STOP
key or a software
trigger command
may be used to generate
the System Start pulse for the counter. With external trigger enabled, the
RUN/STOP
key or software
trigger command
arms the unit and the
subsequent external trigger pulses replace the T
0
pulses.
•
Single Shot Mode
In ‘Single Shot’
mode
, the System Timer is bypassed and the T
0
pulse is
generated directly from the System Start pulse.
The T
0
pulses are distributed to the Channel Start input of all of the
Channel Timers.
The Channel Timer functions as a non-retriggerable, delayed, one shot
pulse generator. This means that the timer will only generate one delayed
pulse for every Channel Start pulse received. Once the channel timer has
started counting, additional start pulses will be ignored until the pulse has
been completed (non-retriggerable). The Channel Start pulse for each
channel is provided by the internal T
0
pulse.
Channel Timer Functions
Whether or not a pulse is generated for each T
0
pulse is determined by
the channel
enable
setting. Pulses are defined by a time
delay
, from their
sync or start pulse to the active edge, a time
width
over which the pulse is
active, and an
amplitude
during the active portion of the pulse.
•
Selecting Menus
Navigating the 9730 Front Panel
Parameters are grouped in menus, selectable using the function keys. To
select the output channel parameters, press the letter key corresponding
to the desired channel. To select other menus, including the channel test
menus, press the
FUNC
key and then the key corresponding to the
desired function.
