Syntax
INT is_SetExternalTrigger (HIDS hf, INT nTriggerMode)
Description for EAGLE
is_SetExternalTrigger() activates the trigger mode. This function call sets the edge on which an action takes place:
•IS_SET_TRIG_HI_LO: action on high low edge
•IS_SET_TRIG_LO_HI: action on low high edge
The trigger pulse width must be larger than 20 m otherwise this cannot be detected surely
Two trigger modes are available:
1.If the trigger input is active, after the is_FreezeVideo() function call and input of the trigger signal, the following (half) frame is acquired (next following VSYNC). Whether a full or half frame is acquired depends upon the setting of is_SetCaptureMode().
2.If the trigger input is active, the current digitizing is stopped when the is_StopLiveVideo() function is called and when there is a trigger signal input. The frame or half frame which is currently being digitized is acquired. Whether half-frame processing should follow depends upon the setting in the is_SetCaptureMode() function. The requirement for this is previous live mode acquisition (is_CaptureVideo()).
3.Is the trigger input switched actively, digitizing is started after call of function is_CaptureVideo() with every arrival of a trigger signal.
Different modes are set depending upon the called function (is_FreezeVideo(), is_StopLiveVideo(), is_CaptureVideo()). The parameter WAIT is added to this function (timeout criteria).
Description for FALCONquattro/FALCONquattro Express
is_SetExternalTrigger() activates trigger port and interrupt processing when recognizing a trigger event (EVENT processing). Is a trigger event detected, a user-defined event is signalized. The event must be initialized with functions is_InitEvent() and is_EnableEvent() (parameter IS_SET_EVENT_EXTTRIG). The following function modes can be set with is_SetExternalTrigger():
•EVENT signalling during Low-Hi trigger. Only trigger inputs are reported detecting a Low-Hi trigger event.
•EVENT is signalled during Hi-Low trigger. Only trigger inputs are reported detecting a Hi-Low trigger event.
•EVENT signalling with Low-Hi and Hi-Low trigger. Only trigger inputs are reported detecting a Low-Hi or Hi-Low trigger event.
•EVENT signalling during status change of trigger inputs. Current states of all trigger input states are reported.
•Polling operation. Current states of all trigger inputs can be read manually.
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When using the FALCONquattro/FALCONquattro Express board only the second device can control the trigger and digital I/O lines. Therefore the device no. 2 has to be initialized with is_InitBoard() and its board handle has to be used for is_SetExternalTrigger(). |
Example FALCONquattro/FALCONquattro Express
Activate EVENT signalling for trigger inputs 1 to 4 during Low-Hi trigger (see also example program TriggerIO):
// Initialise the second device (only the second device control the I/O)
hi = (HIDS)2;
is_InitBoard(&hi, hwnd);
. . .
is_InitEvent(hi, hEv, IS_SET_EVENT_EXTTRIG);
is_EnableEvent(hi, IS_SET_EVENT_EXTTRIG);
is_SetExternalTrigger(hi, IS_SET_TRIG_MASK | 0x0F);
is_SetExternalTrigger(hi, IS_SET_TRIG_EVENT_ONLY | IS_SET_TRIG_LO_HI);
// after EVENT-Signalling:
Status = is_SetExternalTrigger(hi, IS_GET_TRIGGER_STATUS);
Parameters
hf |
Frame grabber handle |
nTriggerMode |
|
IS_SET_TRIG_OFF |
Disable trigger processing |
IS_SET_TRIG_HI_LO |
Sets active trigger flank to Hi-Low trigger |
IS_SET_TRIG_LO_HI |
Sets active trigger flank to Low-Hi trigger |
IS_SET_TRIG_EVENT_ONLY |
Signals an event when detecting a trigger flank. No active flank can be determined from FALCONquattro/FALCONquattro Express without event processing. |
IS_GET_EXTERNALTRIGGER |
Returns the trigger mode settings |
IS_SET_TRIG_MASK (FALCONquattro/FALCONquattro Express only) |
Sets trigger mask for each trigger input. The mask must be connected with the parameter by logical OR-operation Bit 0: trigger input 1 … Bit 7: trigger input 8 |
IS_GET_TRIGGER_MASK (FALCONquattro Express only) |
Read trigger mask |
IS_GET_TRIGGER_STATUS (FALCONquattro/FALCONquattro Express only) |
Read trigger status (only after signalling of an event). Without event processing the current status of all trigger inputs is read (polling operation). |
Return value
IS_SUCCESS, IS_NO_SUCCESS or current setting with IS_GET_EXTERNALTRIGGER
