Measurement Computing Data Acquisition Systems rev.10.4 - Manual (Page 110)

Function Usage
Enhanced trigger configuration available through the daqAdcSetTrigEnhanced command allows the
device to detect a trigger start event formed with multiple acquisition channels. The enhanced trigger start
event may be defined as a combination of multiple acquisition channel event conditions that are connected
logically by AND or OR.
To use multi-channel analog triggering, the trigSource parameter needs to be set to
DatsEnhTrigger
. Other trigger sources may used with the WaveBook as well --however,
they can only act upon the first channel defined in the trigger channels array.
The daqAdcSetTrigEnhanced command sets the trigger start event only. The start event defines the
method by which the acquisition is to begin collecting data. When the trigger event is satisfied, the device will
begin to collect post-trigger data. The acquisition will terminate based on the acquisition mode parameter set
in the daqAdcSetAcq command.
The trigger event is based on the channel trigger event for each channel in the trigger sequence. The total
number of trigger channels is defined by the chanCount parameter. Each channel trigger configuration
parameter is a pointer to an array of chanCount length and is defined as follows:
channels - a pointer to an array of actual scan channel numbers; these channels will be assigned
corresponding trigger events.
trigSources - a pointer to an array of trigger sources for which the corresponding A/D trigger events will
be configured on the corresponding channel as defined in the channels array.
gains - a pointer to an array of gains corresponding to the actual A/D channels with the corresponding A/D
channel number as defined in the channels array. This setting applies only for analog trigger channels.
adcRanges – a pointer to an array of A/D ranges for the A/D channels as defined in the corresponding
channels array. This setting applies only for analog trigger channels.
hysteresis – a pointer to an array of hysteresis values for each corresponding A/D channel as defined in
the channels array.
level- a pointer to an array of level values for which, when satisfied, will set the trigger event for the
corresponding channel as defined in the channels array.
opStr- a string that establishes the logical relationship between the individual channel trigger events and the
global acquisition trigger condition. Currently, the string can be defined as “*” to perform an AND operation,
or “+” to perform an OR operation on the individual channel trigger events. These two logical connections can
be used to formulate global A/D trigger conditions. If the AND operation is selected, then all trigger channels
must be in the triggered condition for the trigger event to occur. If the OR operation is selected, then any of
the trigger channels can be in the triggered condition for the trigger event to occur.
trigSensitivity – an array of trigger sensitivity definitions for a specified trigger event on the
corresponding channel as defined in the channels array.
Prototypes
C/C++
daqAdcSetTrigEnhanced(DaqHandleT handle, DaqAdcTriggerSource *trigSources,
DaqAdcGain *gains, DaqAdcRangeT *adcRanges, DaqEnhTrigSensT
*trigSensitivity, PFLOAT level, PFLOAT hysteresis, PDWORD channels, DWORD
chanCount, char *opStr);
Visual BASIC
VBdaqAdcSetTrigEnhanced&(ByVal handle&, ByRef trigSources&, ByRef gains&,
ByRef adcRanges&, ByRef trigSens&, ByRef levels!, ByRef hysteresis!, ByRef
chan&, ByVal CHANCOUNT&, ByRef opStr&)
Program References
None
4.2-54 Daq API Command Reference 988594 Programmer’s Manual