CAPLfunctionVTSStartTrigger

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CAPL Functions » VT System » StartTrigger

StartTrigger

Valid for: CANoe DE • CANoe:lite DE

Note
The function can only be called on system variable namespaces of appropriate channels of VT System modules.

Method Syntax

long SysVarNamespace.StartTrigger (eVTSTrigger Trigger);

Description

The function starts the specified trigger. It also resets the event counter system variable that is associated to the trigger to 0. To use a trigger it has to be configured using the functions SetTriggerParams and SetTriggerParamsEx.

You can find additional information about VT System triggers on the page Triggers.

Parameters

• Trigger: Specifies which trigger is configured.
  VT1004/VT1104 module: Values see eVTSTrigger

Return Values

• 0: Successful call
• -1: Call error
• -2: The namespace on which the command was called does not exist, is not a valid VT System namespace or does not support this command.

Example

Example: CAPL Test Module
The following example shows how triggers can be used to measure the width of a pulse that is the distance between the rising and falling edge of a pulse.

variables
{
   int64 gRiseTime = 0;
   int64 gFallTime = 0;
}

void MainTest ()
{
   MeasurePulseLength();
}

void MeasurePulseLength()
{
   dword trigger1EventCount = 0;
   dword trigger2EventCount = 0;
   int64 pulseWidth = 0;

   enum eVTSTrigger trigger = eVTSTrigger1;
   enum eVTSTriggerSourceChannel sourceChannel = eVTSTriggerSourceChannel1;
   enum eVTSTriggerEdgeType edgeType = eVTSTriggerEdgeTypeRising;
   dword preTriggers = 0;

   double minPulseWidth = 0.0;

   // configure two triggers (one for the rising and one for the falling edge)
   trigger = eVTSTrigger1;
   sourceChannel = eVTSTriggerSourceChannel1;
   edgeType = eVTSTriggerEdgeTypeRising; // rising edge
   preTriggers = 0; // no other trigger as precondition
   minPulseWidth = 0.002; // pulse must have a width of at at least 2ms

   sysvar::VTS::IgnitionChannels.SetTriggerParams( trigger, sourceChannel, edgeType);
   sysvar::VTS::IgnitionChannels.SetTriggerParamsEx( trigger, minPulseWidth, 0.0, preTriggers, 0, 0, eVTSTriggerTypeEdge);

   trigger = eVTSTrigger2;
   sourceChannel = eVTSTriggerSourceChannel1;
   edgeType = eVTSTriggerEdgeTypeFalling; // falling edge
   preTriggers = 1; // first bit set: trigger 1 must be activated as a precondition

   sysvar::VTS::IgnitionChannels.SetTriggerParams( trigger, sourceChannel, edgeType);
   sysvar::VTS::IgnitionChannels.SetTriggerParamsEx( trigger, 0.0, 0.0, preTriggers, 0, 0, eVTSTriggerTypeEdge);

   TestWaitForTimeout( 50); // wait some time to make sure the settings are transferred

   // start triggers
   trigger = eVTSTrigger1;
   sysvar::VTS::IgnitionChannels.StartTrigger( trigger);
   trigger = eVTSTrigger2;
   sysvar::VTS::IgnitionChannels.StartTrigger( trigger);

   // wait some time until a pulse has occurred
   TestWaitForTimeout( 1000);

   // check if pulse was detected and output pulse width
   trigger1EventCount = @sysvar::VTS::IgnitionChannels::Trigger1EventCount;
   trigger2EventCount = @sysvar::VTS::IgnitionChannels::Trigger2EventCount;

   if (trigger1EventCount > 0 && trigger2EventCount > 0)
   {
      pulseWidth = gFallTime - gRiseTime;
      Write( "Pulse width: %.3f µs", (pulseWidth/1000.0));
   }
   else
   {
      Write("No pulse detected!");
   }
}

on sysvar_update sysvar::VTS::IgnitionChannels::Trigger1Event
{
   // save time stamp of rising edge when event occurs
   gRiseTime = sysGetVariableTimeNS( this);
}

on sysvar_update sysvar::VTS::IgnitionChannels::Trigger2Event
{
   // save time stamp of falling edge when event occurs
   gFallTime = sysGetVariableTimeNS( this);
}

vtsStartTrigger