Signametrics Corporation SMU2060, Operator'S Manual

Page: 126 / 182

Signametrics
126
Return Value
The return value is one of the following constants.
Value Meaning
DMM_OKAY Function succeeded.
Negative Value Error code
Example
status = DMMSetAutoRange(0, TRUE); /* enable autoranging */
DMMSetBuffTrigRead
SMU2060  SMU2064 
Description
Setup the DMM for Triggered operation.
#include "SMU2060.h"
#include "USBDMMUser.h"
int
DMMSetBuffTrigRead(int
nDmm
, int
iSettle
, int
iSamples
, int
iEdge
)
Remarks
Setup the SMU2060 for external hardware trigger operation. Following reception of this
command the DMM enters a wait state. After reception of an external trigger edge of
iEdge
polarity, the DMM takes
iSettle
+ 1 readings at the set measurement function,
range, Aperture and Read Interval; and stores the last reading in the in an internal buffer.
This process is repeated for
iSamples
. This function is particularly useful in conjunction
with a triggering instruments such as the SM4042 or SMX4032 relay scanner. No
autoranging, function or ranges changes allowed while the DMM is waiting for triggers.
The number of trigger edges must be equal or greater than
iSamples
to properly terminate
this mode. Any trigger received following iSamples is ignored. Between the time this
command is issued and the time the buffer is read, no other command should be sent to
the DMM with the exception of
DMMDisarmTrigger command, which terminates this
mode, and DMMReady which monitors readyness. This function is usable for VDC,
VAC, Ohms, IAC, IDC and RTD measurements.
Use the DMMReady to monitor when the DMM is ready (following trigger(s) and the
reading of
iSamples
). When ready, you can read up to
iSamples
, using
DMMReadBuffer or DMMReadBufferStr functions. Once DMMReady returns
TRUE , it should not be used again prior to reading the buffer, since it prepares the buffer
for reading when it detects a ready condition.
Parameter Type/Description
nDmm
int Identifies the DMM. DMMs are numbered starting with zero.
iSettle
int The number of setteling measurements, prior to read value. Must
be set between 0 and 250.
iSamples
int The number of samples the DMM takes following the same
number of trigger pulses. This number must be between 1 and 80 or
120 depending on aperture.
iEdge
Int The edge polarity of the trigger signal. 1 for Positive, or leading
edge, and 0 for negative or trailing edge trigger.
Return Value
The return value is one of the following constants.