Racal Instruments 3151, User Manual

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3151 And 3151A User Manual
Getting Started 1-6
SYNC Output
The SYNC output generates a single TTL pulse for synchronizing
other instruments (i.e., an oscilloscope) to the output waveform. The
SYNC signal always appears at a fixed point relative to the
waveform. The SYNC output generates a single point pulse for
standard and arbitrary waveforms. The location of the SYNC signal
along the waveform is programmable from point 2 to the last point on
the waveform.
External Clock Input
The external clock input is available for those applications required to
run the complete system off the same clock. Normally, this input is
disabled. When enabled, the clock at this input replaces the internal
clock generator and the output waveform will begin generating
waveforms with clock rates that are present at the external clock
input. Do not confuse the clock frequency with the frequency of the
waveform. The actual frequency of the output waveform depends on
the number of points that are allocated for the waveform. For
example, if the external clock is 10 MHz and the number of points
that were assigned to the active segment is 1000, the output
frequency will be 10 kHz (10 MHz divided by the number of points).
The external clock input accepts fixed level TTL signals within the
range of DC to 100 MHz.
Reference Clock
Output
The reference clock output is a 10 MHz fixed level TTL signal that is
derived directly from the internal 10 MHz reference crystal. This
output may serve as a reference clock to other instruments or
devices that require a 10 MHz clock synchronization signal.
Trigger Input
The trigger input accepts signals that stimulate the Model
3151/3151A to output waveforms. The trigger input is inactive when
the instrument is in continuous operating mode. When placed in
trigger, gated or burst mode, the trigger input is made active and
waits for the right condition to trigger the instrument. In trigger and
burst modes, the trigger input is edge sensitive, i.e., it senses
transitions from high to low or from low to high to trigger the Model
3151/3151A. The direction of the transition is programmable. The
trigger input accepts fixed level TTL signals.
In gated mode, the trigger input is level sensitive, i.e., the Model
3151/3151A is gated when the level is high and idle when the level is
low. Level sensitivity may be programmed for the trigger input.