imaqIOPulseCreate
Format
rval = imaqIOPulseCreate(IMAQIO_SESSION id,
IMAQIOTimebase delayTimebase, unsigned long delay,
IMAQIOTimebase widthTimebase, unsigned long width,
IMAQIOSignalType triggerSignalType, unsigned long triggerSignalNumber, IMAQIOPolarity triggerSignalPolarity,
IMAQIOSignalType outputSignalType, unsigned long outputSignalNumber, IMAQIOPolarity outputSignalPolarity,
IMAQIOPulseMode pulseMode, IMAQIO_PULSE_ID* pulseID);
Purpose
Configures one of the six pulse generators for the NI-IMAQ I/O device. Refer to your hardware documentation for more information about connecting and configuring the pulse generators.
Parameters
| Name | Type | Direction |
| id | IMAQIO_SESSION | input |
| delayTimebase | IMAQIOTimebase | input |
| delay | unsigned long | input |
| widthTimebase | IMAQIOTimebase | input |
| width | unsigned long | input |
| triggerSignalType | IMAQIOSignalType | input |
| triggerSignalNumber | unsigned long | input |
| triggerSignalPolarity | IMAQIOPolarity | input |
| outputSignalType | IMAQIOSignalType | input |
| outputSignalNumber | unsigned long | input |
| outputSignalPolarity | IMAQIOPolarity | input |
| pulseMode | IMAQIOPulseMode | input |
| pulseID | IMAQIO_PULSE_ID* | output |
Parameter Discussion
id is the ID of the session to create a pulse on.
delayTimeBase is the timebase of the pulse delay. The following values are valid for this parameter:
| Name | Constant | Description |
| IMAQIO_TIMEBASE_ENCODER_TICKS | 4 | Defines the delay or width in encoder counts |
| IMAQIO_TIMEBASE_MICROSECONDS | 5 | Defines the delay or width in microseconds. |
delay is the pulse delay.
widthTimeBase is the timebase of the pulse width. The following values are valid for this parameter:
| Name | Constant | Description |
| IMAQIO_TIMEBASE_MICROSECONDS | 5 | Defines the delay or width in microseconds. |
width is the width of the pulse.
triggerSignalType is the type of signal to trigger on. The following values are valid for this parameter:
| Name | Constant | Description |
| IMAQIO_SIGNAL_ISO_IN | 2 | Use isolated inputs 5, 8, and 12 to trigger a pulse. |
| IMAQIO_SIGNAL_STATUS | 4 | Signal status signals are internal timing signals, including the immediate trigger mode. |
| IMAQIO_SIGNAL_TTL_IN | 5 | Use either TTL input 0 or 1 to trigger a pulse. |
triggerSignalNumber is the line number of the signal to trigger on. If you set triggerSignalType to IMAQIO_SIGNAL_STATUS, use IMAQIO_STATUS_SIGNAL_NONE to cause the pulse to start immediately upon calling imaqIOPulseStart.
triggerSignalPolarity is the polarity of the trigger as defined by the following constants:
| IMAQIO_POLARITY_HIGH_TRUE | Triggers the pulse on a rising edge. |
| IMAQIO_POLARITY_LOW_TRUE | Triggers the pulse on a falling edge. |
outputSignalType is the type of signal to create a pulse on. The following values are valid for this parameter:
| Name | Constant | Description |
| IMAQIO_SIGNAL_ISO_OUT | 3 | ISO output signals are general-purpose outputs. |
| IMAQIO_SIGNAL_TTL_OUT | 6 | TTL output signals are general-purpose outputs. |
outputSignalNumber is the line number of the signal to create the pulse on.
outputSignalPolarity is the polarity of the pulse output as defined by the following constants:
| IMAQIO_POLARITY_HIGH_TRUE | Drives the line high during the pulse assertion, which is dictated by the width. |
| IMAQIO_POLARITY_LOW_TRUE | Drives the line low during the pulse assertion, which is dictated by the width. |
pulseMode is a value that indicates if the pulse is generated once or continuously. pulseMode can be one of the following constants:
| PULSE_MODE_TRAIN | Pulse is generated continuously after the trigger is asserted. Choose this option to generate a continuous pulse train that is inactive for the time specified in the delay parameter and active for the time specified in the width parameter. When the pulse train is started, it continues periodically until you call imaqIOPulseStop, imaqIOPulseDispose, or imaqIOClose.
This mode is valid only if you set triggerSignalType to IMAQIO_SIGNAL_STATUS, and triggerSignalNumber is set to IMAQIO_STATUS_SIGNAL_NONE. |
| PULSE_MODE_SINGLE | Pulse is generated only one time in response to the triggering condition being satisfied. If triggerSignalType is set to IMAQIO_SIGNAL_STATUS and triggerSignalNumber is set to IMAQIO_STATUS_SIGNAL_NONE, pulse generation will start immediately after calling imaqIOPulseStart. Otherwise, the pulse will start after the respective trigger line is asserted. In either case, after the trigger condition is satisfied, the output line stays inactive for the time specified in the delay parameter and becomes active for the time specified in the width parameter. |
| PULSE_MODE_SINGLE_REARM | Pulse occurs one time on each trigger occurrence. Choose this option to generate a rearmed single-shot pulse. On every occurrence of the trigger, the output line stays inactive for the time specified in the delay parameter and becomes active for the time specified in the width parameter. When the pulse is started, output toggles for each occurrence of the trigger until you call imaqIOPulseStop, imaqIOPulseDispose, or imaqIOClose. This mode works only when the application is configured to trigger on the TTL In or ISO In lines. |
pulseID is a pointer to a variable to receive the pulse ID. If the function succeeds, the variable is populated with a valid PULSE_ID that you can use in subsequent functions.
Return Value
This function returns 0 on success. On failure, this function returns an error code. For information about the error code, call imaqIOGetErrorText.