External Digital Trigger - ICP DAS USA ET-7H16M Series User Manual

3.2.2.

External Digital Trigger

There are two external digital trigger, Pre-trigger and Post-trigger.
Pre-trigger
This trigger type is used when you want to collect data before an external trigger event. Send a
start command from PC over the Ethernet to PET-7H16M to start the AD conversion. The analog
input value is continuously acquired and converted to digital data. When the trigger event occurs,
the AD conversion is stopped Send a command to get the specified sampling counts of data over
the Ethernet.
Post-trigger
This trigger is used in application when you want to collect data after an external trigger event.
Send a start command from PC over the Ethernet to PET-7H16M to start the acquisition. The A/D
conversion is started actually when the external digital signal is input. The analog input value is
continuously acquired and converted to digital data until the total number of samples reaches.
Send a command to get the all acquisition data over the Ethernet.
There are some parameters that need to be specified:

Sampling rate (1 to 200K Hz)

Scan channels

Sampling Count (Maximum 30,000,000 records)

The trigger mode can be set to Post-trigger or Pre-trigger.

The negative condition is allowed in digital trigger. It is used when a falling edge is detected
on the digital signal. The negative condition is used when it triggers from high to low.
PET-7H16M Series User Manual, version 1.0.1 P.36