Fluke 8588A Operator's Manual page 123

Example 4
In the examples so far, the Holdoff setting has been left as Auto. This causes the
Trigger subsystem to wait for a measurement to complete before it continues
around the loop, making operation generally more intuitive. However, in some
cases this may not be the desired behavior.
Measurement: An external 1 MHz signal is being applied to the rear panel TRIG
IN BNC and the requirement is to make measurements synchronously with this
signal, but at a rate of only 10,000 measurements per second.
Solution: From defaults, set the Trigger Event to External and the
Triggers/reading (ECount) to 100. Set the Holdoff to zero. The aperture must be
short enough to support 10,000 measurements per second, for dcv a suitable
value would be 50 μs.
This works by requiring 100 cycles of the external trigger signal for each
measurement made. However, it must count all incoming cycles and not ignore
those during the measurement/holdoff period. Setting Holdoff to zero value
makes the Trigger subsystem independent of the measurement process.
Example 5
Measurement: Measure the overshoot of a (slow) rising edge, which may or may
not have ringing.
Solution: Set the DCV aperture to 1 s. In Trigger Setup, set Trigger Event to
Internal, + slope, 90% of Range. Set the Holdoff to 10 seconds to ensure any
ringing is ignored. When the analog input reaches 90% of range, the triggering
subsystem makes one measurement, then waits for the remainder of the holdoff
time before waiting for the next event.
This example uses long time intervals to illustrate the timing between holdoff and
the start of an acquisition. The Trigger subsystem waits for the rising edge,
makes a measurement, but then remains in the holdoff state for 9 more seconds
(10 since the measurement was began) before returning to wait for another rising
edge. Any ringing that occurred during that time would have been ignored. In
practice, this measurement is better made with a 10 second timer event in Arm2
or Arm1 instead of using holdoff, as holdoff is typically used to eliminate "Trigger
too fast" errors. Furthermore, the exact point in the Trigger subsystem at which
the holdoff timer is started is device dependent, and may be different in other
products.
Reference Multimeter and 8 ½ Digit Multimeter
Triggering Measurements
119