Specifies the trigger level for the Ready For Trigger event. This event indicates to an external device responsible for sending triggers that the VNA is ready to receive the trigger.

You do not need to use a selector string to configure or read this property for the default signal instance. Refer to the Selector Strings topic for information about the string syntax for named signals.

The default value is Active Low.

The Trigger Mode you configure determines the number of triggers needed for the VNA to complete the measurement. It also affects how often the ready for trigger event changes polarity. For example, when measuring S11 and S22 using a 2-port VNA with Trigger Type set to Digital or Software, and the ready for trigger event polarity set to Active Low, the polarity behavior for various Trigger Mode will be as follows:

1.

Trigger Mode is Signal: the VNA waits for only one instance of the trigger to be asserted before acquiring all data points. When VNA is ready to receive the trigger, the ready event polarity is LOW and switches to HIGH after a trigger is asserted.

2.

Trigger Mode is Sweep: the VNA waits for one instance of the trigger to be asserted before acquiring all data points that share a source port. When VNA is ready to receive the first trigger, the ready event polarity is LOW and switches to HIGH after the first trigger is asserted. The polarity remains HIGH until VNA completes all the acquisitions that require VNA port 1 as the source. When VNA is ready to receive the second trigger, the ready event polarity switches to LOW. Upon assertion of the second trigger, the polarity switches to HIGH.

3.

Trigger Mode is Point: the VNA waits for one instance of the trigger to be asserted before acquiring each data point. When VNA is ready to acquire a data point, the ready event polarity is LOW, and switches to HIGH after a trigger is asserted. The polarity remains HIGH until VNA is ready to acquire the next data point.

4.

Trigger Mode is Segment with segmented sweep across two frequency segments: the VNA waits for one instance of the trigger to be asserted before acquiring all data points within a segment that share a source port. When VNA is ready to receive the first trigger, the ready event polarity is LOW and switches to HIGH after the first trigger is asserted. The polarity remains HIGH until the VNA completes all the acquisitions for the first segment that require VNA port 1 as the source, and until the VNA is ready to receive the second trigger. When VNA is ready to receive the second trigger, the ready event polarity switches to LOW. Upon assertion of the second trigger, the polarity switches to HIGH. The polarity remains HIGH until VNA completes all the acquisitions for the second segment that require VNA port 1 as the source. The VNA is then ready to receive the second trigger, at which point the ready event polarity switches to LOW. Upon assertion of the second trigger, the polarity switches to HIGH and remains HIGH until the VNA completes all acquisitions for the second segment that require VNA port 1 as the source. The ready event polarity follows the same behavior for the third and fourth trigger instances, which are required to complete all acquisitions for the first and second segments that require VNA port 2 as the source, respectively.

Remarks

The following table lists the characteristics of this property.

Short Name Ready For Trigger Event Level
Data type ci32.png
Permissions Read/Write
High-level VIs N/A
Resettable Yes
Active High 0

Event level is HIGH when analyzer is ready to receive trigger.
Active Low 1

Event level is LOW when analyzer is ready to receive trigger.