Channel Timer Functions
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 start pulse received. Once the channel timer has started counting, addi-
tional start pulses will be ignored until the pulse has been completed (non-
retriggerable). The start pulse for each channel is provided by the internal T
o
pulse generated by the Internal System Timer. Whether or not a pulse is gener-
ated for each T
o
pulse is determined by the Channel Mode Generator. Standard
modes include:
Normal
A pulse is generated for each T
o
pulse.
Single Shot
One pulse is generated at the first T
o
pulse, after which
output is inhibited.
Burst
A pulse is generated for each T
o
pulse, 'n' times, after
which output is inhibited.
Duty Cycle
n pulses are generated for each T
o
pulse after which
the output is inhibited for m times. The cycle is then
repeated.
Different modes may be selected for each output, allowing a wide variety of
output combinations. Each output may also be independently disabled or gated
(using the external gate input).
Output Multiplexer
The output of the Channel Timers are routed to a set of multiplexers. This allows
routing of any or all Channel Timers to any or all of the unit outputs. In the normal
mode of operation, the output of the nth Channel Timer is routed to the Tnth
output connector. As an example, if a double pulse is required on Channel A
output, one can multiplex the Channel A timer with the Channel B timer adjusting
each timer to provide the necessary pulses.
Dependent & Independent Timing Events
The 9520 allows the user to control the relationship between the Channel Timers
by setting the sync source for each timer. Independent events are all timed
relative to the internal T
o
start pulse. Dependent events may be linked together
by setting the sync source to the controlling event. This allows the instrument to
match the timed events and adjustments can be made in one event without
detuning the timing between it and a dependent event.
Navigating the 9520 Front Panel
Selecting Menus
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 advanced channel menus, press
the FUNC key and then the key corresponding to the desired function.
