Section 3: Functions and features
Model DMM7510 7½ Digit Graphical Sampling Multimeter Reference Manual
3-64
DMM7510-901-01 Rev. B / May 2015
Command interface triggering does not generate action overruns. The triggers are processed in the
order that they are received in the Model DMM7510 command queue. The Model DMM7510 only
processes incoming commands when no commands are running. Unprocessed input triggers can
cause an overflow in the command queue. It is important to make sure a script processes triggers
while it is running.
If you are using a test script using TSP, the command queue can fill up with trigger entries if over 50
*TRG
messages are received while a test script is running, even if the script is processing triggers.
You can avoid this by using the
(on page 8-224) attribute, and by using
trigger.wait()
calls that remove the
*TRG
messages from the command queue. If the command
queue fills with too many trigger entries, messages such as
abort
are not processed.
Triggering using hardware lines
You can use the digital I/O lines, external I/O, and TSP-Link
®
synchronization lines to synchronize the
operations of the Model DMM7510 with those of external instruments. You can use these lines to
synchronize the Model DMM7510 with other TSP-enabled instruments, including other Model
DMM7510 instruments. You must use the digital I/O lines or external I/O line to synchronize the
Model DMM7510 with other Keithley products or other non-Keithley products.
The lines are configured and controlled similarly. See Digital I/O,
(on page 3-59) for more information about connections
and configuration and control of the lines.
Analog triggering overview
You can use input signals for triggering when you are measuring current or voltage using the DC
measure or digitize functions. The instrument compares the signals, before they are processed into
measurements, to the settings that you define. The trigger occurs when the signal satisfies the
specified conditions. Triggers generated by these comparisons are called analog triggers. You can
use analog triggers to trigger instrument action in the same ways that you use other trigger types.
Analog triggers should be set after other instrument settings. In particular, if you are using a measure
function, select the function, turn autozero off, and select a specific range before setting up analog
triggers.
Analog trigger mode
To set up an analog trigger, you need to define the analog trigger mode. The mode defines how the
instrument processes the signal that generates the trigger event. The available modes are edge,
pulse, and window.
When edge is selected, the trigger event occurs when the signal crosses a level that you define. You
also specify if the trigger occurs on the rising or falling edge of the signal.
The pulse and window modes are typically used to spot signal anomalies.
When pulse is selected, the trigger event occurs when a pulse satisfies the amplitude, polarity, and
pulse width requirements that you specify.
When window is selected, the trigger event occurs when the signal enters or exits a window that is
defined by low and high signal levels.
