Section 3: Functions and features
Model 2461 Interactive SourceMeter® Instrument Reference Manual
3-110
2461-901-01 A/November 2015
Digitize block
When trigger model execution reaches the block:
1. The instrument begins digitizing measurements.
2. The trigger model execution waits for the measurement to complete.
3. The instrument places the measurements into the specified reading buffer.
If you are defining a user-defined reading buffer, you must create it before you define this block.
When you set the count to a finite value, trigger model execution remains at the block until all digitize
measurements are complete (at least 2 µs). If you set the count to infinite, the trigger model executes
subsequent blocks and digitizing continues in the background until the trigger model execution
reaches another digitize block or until the trigger model ends. The digitize block completes and
moves on to the next block at the end of the aperture time, not the sample rate time.
For example, if there are two readings at a sample rate of 20,000 samples per second (50
µ
s apart)
with an aperture of 1
µ
s, with a delay of 100
µ
s, the delay starts at 51
µ
s. The first reading occurs at 0
µ
s and the second starts at 50
µ
s, but it is completed at 51
µ
s because the aperture is only 1
µ
s. If
the aperture is set to Auto, the first reading is at 0
µ
s, the second starts at 50
µ
s, and the delay starts
at 100
µ
s.
The digitize block must be used with a digitize function. The trigger model will not run if a measure
function is selected.
A trigger model that contains a digitize block may appear to hang in the wait block because it is
making many measurements in one block.
There is a 2
µ
s delay after the digitize block makes the last measurement in the count.
When you select the digitize block, the following options are available.
Setting
Description
Reading Buffer
The name of the buffer where the measurement is stored
Count
Specifies the number of readings to make before moving to the
next block in the trigger model
Timing blocks
You can use the timing blocks to control the timing of actions in the trigger model. The timing blocks
include the wait and delay blocks.
Wait block
The wait block causes the trigger model to stop and wait for an event or set of events to occur before
continuing. You can specify up to three events for each wait block.
The event can occur before the trigger model reaches the wait block. If the event occurs after the
trigger model starts but before the trigger model reaches the wait block, the trigger model records the
event. By default, when the trigger model reaches the wait block, it executes the wait block without
waiting for the event to happen again (the clear parameter is set to never).
The instrument clears the memory of the recorded event when the trigger model exits the wait block.
It also clears the recorded trigger event when the clear parameter is set to enter.
All items in the list are subject to the same action — you cannot combine
AND
and
OR
logic in a single
wait block.