imgSessionTriggerRead2
- Updated2023-02-21
- 1 minute(s) read
Usage
rval imgSessionTriggerRead2(SESSION_ID sid, IMG_SIGNAL_TYPE triggerType, uInt32 triggerNumber, uInt32 polarity, uInt32* status);
Purpose
Reads the current value of the specified trigger line.
Parameters
| Name | Type | Direction |
| sid | SESSION_ID | input |
| triggerType | IMG_SIGNAL_TYPE | input |
| triggerNumber | uInt32 | input |
| polarity | uInt32 | input |
| status | uInt32* | output |
| rval | Int32 | output |
Parameter Discussion
sid: valid SESSION_ID.
triggerType: type of trigger line to use. triggerType can be one of the following constants:
 |
Note To use the ISO_IN or RS422_IN signals on the NI PCI-1426, select External as the Trigger Type for your function and choose ISO In or RS-422 In as the Signal Level for the trigger line in Measurement & Automation Explorer (MAX). |
| IMG_SIGNAL_EXTERNAL |
| IMG_SIGNAL_RTSI |
| IMG_SIGNAL_ISO_IN |
| IMG_SIGNAL_ISO_OUT |
triggerNumber: number of the trigger line to use.
polarity: polarity of the trigger line. polarity can be one of the following constants:
| IMG_TRIG_POLAR_ACTIVEL | Asserts the trigger line when the signal is low. |
| IMG_TRIG_POLAR_ACTIVEH | Asserts the trigger line when the signal is high. |
status: pointer to a variable to receive the state of the trigger. Upon return, the function sets status to a non-zero value if the trigger is asserted and to a zero value if the trigger is unasserted.
Return Value
This function returns 0 on success. On failure, this function returns an error code. For information about the error code, call imgShowError.