Sleep Commands

Sleep commands can be inserted in a path sequence to pause execution for the specified period. The interpolating axes will decelerate to a stop wherever there is a sleep command in the path sequence, and then the advMotion for the remaining path will resume after the specified period of time elapses. Smoothing will not be applied between linear interpolations separated by a sleep command.

Sleep Command Example

The following sample code executes a path containing a sleep command.

//Create the path interpolation with look ahead buffer
wmxlib_AdvancedMotion->advMotion->CreatePathIntplLookaheadBuffer(0, 1000);

//Configure the path interpolation with look ahead channel
AdvMotion::PathIntplLookaheadConfiguration conf;

conf.axisCount = 2;
conf.axis[0] = 0;
conf.axis[1] = 1;
conf.compositeVel = 1000;
conf.compositeAcc = 2000;
conf.sampleDistance = 100;

wmxlib_AdvancedMotion->advMotion->SetPathIntplLookaheadConfiguration(0, &conf);

//Add the path interpolation with look ahead commands
AdvMotion::PathIntplLookaheadCommand path;

path.numPoints = 4;

path.point[0].type = AdvMotion::PathIntplLookaheadSegmentType::Linear;
path.point[0].data.linear.axisCount = 2;
path.point[0].data.linear.axis[0] = 0;
path.point[0].data.linear.axis[1] = 1;
path.point[0].data.linear.target[0] = 1000;
path.point[0].data.linear.target[1] = 0;
path.point[0].data.linear.smoothRadius = 300;

path.point[1].type = AdvMotion::PathIntplLookaheadSegmentType::Linear;
path.point[1].data.linear.axisCount = 2;
path.point[1].data.linear.axis[0] = 0;
path.point[1].data.linear.axis[1] = 1;
path.point[1].data.linear.target[0] = 1000;
path.point[1].data.linear.target[1] = 1000;
path.point[1].data.linear.smoothRadius = 300;

path.point[2].type = AdvMotion::PathIntplLookaheadSegmentType::Sleep;
path.point[2].data.sleep.milliseconds = 1000;

path.point[3].type = AdvMotion::PathIntplLookaheadSegmentType::Linear;
path.point[3].data.linear.axisCount = 2;
path.point[3].data.linear.axis[0] = 0;
path.point[3].data.linear.axis[1] = 1;
path.point[3].data.linear.target[0] = 0;
path.point[3].data.linear.target[1] = 0;

wmxlib_AdvancedMotion->advMotion->AddPathIntplLookaheadCommand(0, &path);

//Execute path interpolation with look ahead
wmxlib_AdvancedMotion->advMotion->StartPathIntplLookahead(0);

//Wait for the path interpolation with look ahead to complete
AdvMotion::PathIntplLookaheadStatus pathStatus;
wmxlib_AdvancedMotion->advMotion->GetPathIntplLookaheadStatus(0, &pathStatus);
while(pathStatus.remainCommandCount > 0) {
    Sleep(10);
    wmxlib_AdvancedMotion->advMotion->GetPathIntplLookaheadStatus(0, &pathStatus);
}

//Move the axes to Idle state
wmxlib_AdvancedMotion->advMotion->StopPathIntplLookahead(0);

//Wait until the path interpolation with look ahead is in Stopped state
wmxlib_AdvancedMotion->advMotion->GetPathIntplLookaheadStatus(0, &pathStatus);
while(pathStatus.state != AdvMotion::PathIntplLookaheadState::Stopped) {
    Sleep(10);
    wmxlib_AdvancedMotion->advMotion->GetPathIntplLookaheadStatus(0, &pathStatus);
}

//Free the path interpolation with look ahead buffer (normally, the buffer should only be freed at the end of the application)
wmxlib_AdvancedMotion->advMotion->FreePathIntplLookaheadBuffer(0);

The following plots show the two-dimensional trajectory and the velocity of each axis when the above sequence is executed from position (0, 0).

The velocity plot shows that the two axes pause (are at zero velocity) for 1000 cycles (1000 milliseconds at a 1ms cycle time) after the initial advMotion. The position plot shows that no smoothing is applied at the corner of (1000, 1000), even though a smoothing radius was specified, because a sleep command is executed at that corner.