niTClk Configure For Homogeneous Triggers

Configures the properties commonly required for the TClk synchronization of device sessions with homogeneous triggers in a single PXI chassis or a single PC.

Use the niTClk Configure For Homogeneous Triggers VI to configure the properties for the reference clocks, start triggers, reference triggers, script triggers, and pause triggers.

If the niTClk Configure For Homogeneous Triggers VI cannot perform all the steps appropriate for the given sessions, it returns an error. If an error is returned, use the instrument driver VIs and properties for signal routing, along with the following NI-TClk properties:

• Start Trigger Master Session
• Reference Trigger Master Session
• Script Trigger Master Session
• Pause Trigger Master Session

Details

	sessions is an array of session references that are being synchronized. You obtain session references from the instrument driver by using <driver name> Get Session Reference VI, where <driver name> is the name of the instrument driver—for example, the niScope Get Session Reference VI.
	error in describes error conditions that occur before this VI or function runs. status is TRUE (X) if an error occurred before this VI or function ran or FALSE (checkmark) to indicate a warning or that no error occurred before this VI or function ran. The default is FALSE. If status is TRUE, this VI propagates the error and does not do anything else. code is the error or warning code. The default is 0. If status is TRUE, code is a negative error code. If status is FALSE, code is 0 or a warning code. source identifies where an error occurred. The source string includes the name of the VI that produced the error and often offers additional information about the error.
	sessions out passes the array of session references to the next VI.
	error out contains error information. If error in indicates that an error occurred before this VI or function ran, error out contains the same error information. Otherwise, it describes the error status that this VI or function produces. status is TRUE (X) if an error occurred or FALSE (checkmark) to indicate a warning or that no error occurred. code is the error or warning code. If status is TRUE, code is a nonzero error code. If status is FALSE, code is 0 or a warning code. source identifies where and why an error occurred. The source string includes the name of the VI that produced the error and often offers additional information about the error. The LabVIEW Simple Error Handler VI and the LabVIEW General Error Handler VI use the source string to deliver messages that may help you to troubleshoot your application.

niTClk Configure For Homogeneous Triggers Details

Reference Clocks

The niTClk Configure For Homogeneous Triggers VI configures the reference clocks if they are needed. Specifically, if the internal sample clocks or internal sample clock timebases are used, and the reference clock source is not configured—or is set to None (no trigger configured)—the niTClk Configure For Homogeneous Triggers VI configures the following:

• PXI—The reference clock source on all devices is set to be the 10 MHz PXI backplane clock (PXI_CLK10).
• PCI—One of the devices exports its 10 MHz onboard reference clock to RTSI 7. The reference clock source on all devices is set to be RTSI 7.

If the reference clock source is set to a value other than None, the niTClk Configure For Homogeneous Triggers VI does not configure the reference clock source.

Start Triggers

If the start trigger is set to None (no trigger configured) for all sessions, the sessions are configured to share the start trigger. The start trigger is shared by:

• Implicitly exporting the start trigger from one session
• Configuring the other sessions for digital edge start triggers with sources corresponding to the exported start trigger
• Setting the Start Trigger Master Session property to the session that is exporting the trigger for all sessions

If the start triggers are None for all except one session, the niTClk Configure For Homogeneous Triggers VI configures the sessions to share the start trigger from the one excepted session. The start trigger is shared by:

• Implicitly exporting start trigger from the session with the start trigger that is not None
• Configuring the other sessions for digital edge start triggers with sources corresponding to the exported start trigger
• Setting the Start Trigger Master Session property to the session that is exporting the trigger for all sessions

If start triggers are configured for all sessions, The niTClk Configure For Homogeneous Triggers VI does not affect the start triggers. Start triggers are considered to be configured for all sessions if either of the following conditions is true:

• No session has a start trigger that is None
• One session has a start trigger that is None, and all other sessions have start triggers other than None. The one session with the None trigger must have the Start Trigger Master Session property set to itself, indicating that the session itself is the start trigger master

Reference Triggers

The niTClk Configure For Homogeneous Triggers VI configures sessions that support reference triggers to share the reference triggers if the reference triggers are None (no trigger configured) for all except one session. The reference triggers are shared by:

• Implicitly exporting the reference trigger from the session whose reference trigger is not None
• Configuring the other sessions that support the reference trigger for digital-edge reference triggers with sources corresponding to the exported reference trigger
• Setting the Reference Trigger Master Session property to the session that is exporting the trigger for all sessions that support reference trigger

If the reference triggers are configured for all sessions that support reference triggers, The niTClk Configure For Homogeneous Triggers VI does not affect the reference triggers. Reference triggers are considered to be configured for all sessions if either one or the other of the following conditions is true:

• No session has a reference trigger that is None
• One session has a reference trigger that is None, and all other sessions have reference triggers other than None. The one session with the None trigger must have the Reference Trigger Master Session property set to itself, indicating that the session itself is the reference trigger master

Reference Trigger Holdoffs

For acquisition sessions, the niTClk Configure For Homogeneous Triggers VI configures the holdoff attributes (which are instrument driver specific) on the reference trigger master session so that the session does not recognize the reference trigger before the other sessions are ready. This condition is only relevant when the sample clock rates, sample clock timebase rates, sample counts, holdoffs, and/or any delays for the acquisitions are different.

Script Triggers 0, 1, 2, and 3

Note  This section applies to each of Script Triggers 0, 1, 2, and 3.

The niTClk Configure For Homogeneous Triggers VI configures sessions that support script triggers to share them, if the script triggers are None (no trigger configured) for all except one session. The script triggers are shared in the following ways:

• Implicitly exporting the script trigger from the session whose script trigger is not None
• Configuring the other sessions that support the script trigger for digital-edge script triggers with sources corresponding to the exported script trigger
• Setting the Script Trigger Master Session property to the session that is exporting the trigger for all sessions that support script triggers

If the script triggers are configured for all sessions that support script triggers, The niTClk Configure For Homogeneous Triggers VI does not affect script triggers. Script triggers are considered to be configured for all sessions if either one or the other of the following conditions are true:

• No session has a script trigger that is None
• One session has a script trigger that is None, and all other sessions have script triggers other than None. The one session with the None trigger must have the Script Trigger Master Session property set to itself, indicating that the session itself is the script trigger master

Pause Triggers

The niTClk Configure For Homogeneous Triggers VI configures generation sessions that support pause triggers to share them, if the pause triggers are None (no trigger configured) for all except one session. The pause triggers are shared by:

• Implicitly exporting the pause trigger from the session whose script trigger is not None
• Configuring the other sessions that support the pause trigger for digital-edge pause triggers with sources corresponding to the exported pause trigger
• Setting the Pause Trigger Master Session property to the session that is exporting the trigger for all sessions that support script triggers

If the pause triggers are configured for all generation sessions that support pause triggers, The niTClk Configure For Homogeneous Triggers VI does not affect pause triggers. Pause triggers are considered to be configured for all sessions if either one or the other of the following conditions is true:

• No session has a pause trigger that is None
• One session has a pause trigger that is None, and all other sessions have pause triggers other than None. The one session with the None trigger must have the Pause Trigger Master Session property set to itself, indicating that the session itself is the pause trigger master

Note  TClk synchronization is not supported for pause triggers on acquisition sessions.