2470 High Voltage SourceMeter Instrument Reference Manual
Section 8: Triggering
2470-901-01 Rev. A /
May
2019
8-7
Define when to generate a timer event
You can specify when timer events are generated using the SCPI
:TRIGger:TIMer<n>:STARt:GENerate
or TSP
trigger.timer[N].start.generate
command.
When this is set to on, a trigger event is generated immediately when the timer is triggered.
When it is set to off, a trigger event is generated when the timer elapses.
You can watch for a stimulus before starting the timer by using the
SCPI
:TRIGger:TIMer<n>:STARt:STIMulus
command or
trigger.timer[
N
].start.stimulus
command.
You can also set an alarm or time in the future when the timer will start using the seconds and
fractional seconds commands. (SCPI commands
:TRIGger:TIMer<n>:STARt:SEConds
and
:TRIGger:TIMer<n>:STARt:FRACtional
; TSP commands
trigger.timer[
N
].start.seconds
and
trigger.timer[
N
].start.fractionalseconds
.)
Timer action overruns
The timer receives an action overrun when it generates a trigger event while a timer delay is still in
progress. Use the status model to monitor for the occurrence of action overruns. For details, see the
(on page B-1).
Using trigger timers with timing blocks
For precise timing or if you need to synchronize timing with other execution blocks or events, you can
use the SCPI or TSP trigger timer commands with trigger model wait blocks and notify blocks. You
can use the trigger timer commands to add small precise delays or to start measurements or to
overcome variable measurement delays. The 2470 has 1 to 4 independent timers.
For example, you can use a trigger timer to control the delay between non-sequential blocks. After
creating a trigger timer, you can insert a notify block to start the timer at a specific point in the trigger
model. You could then add a wait block to wait for the timer to expire.
Another example is a measure block that takes a variable amount of time. To ensure a precise time
between measurements, you can create a trigger timer and define it to be a fixed interval that is
longer than the longest possible measurement. Then you can set up the trigger model to include:
•
A notify block that starts the trigger timer
•
A measure block that makes a measurement
•
A wait block that waits for the timer to expire
•
A branch counter block that iterates some number of times