Operator`s manual

109 Signametrics
DMMSetTrigR
SM2040 ; SM2042 ;
Description
clude "sm20
clude "UserD
int DMMSetTri
Remarks Setup the SM20 ption
of this command the DMM enters a wait state. After reception of an external
ge polarity, the DMM takes iSettle + 1 readings at the set
measurement function, range, and reading rate; and sends the last reading to the
PC. This process is repeated for iSamples. iSamples Trigger pulses must be
issued to complete this process. This function is particularly useful in
tio h as the SM4042 relay scanner. No
autoranging is allowed in this mode. The number of trigger edges must be equal
r les to properly terminate this mode. Following the issue of
the DMMSetTrigRead command, and until the sampling process ends, it is
command. This will prevent an Overrun
ication error. In other words, the rate at which measurement are read
p with the DMM transmission of readings. The DMM has a built in 5
readings FIFO to help with this problem. This function is usable for VDC, VAC,
e DMMReadMeasurement to
, and to read this data.
ead
SM2044 ;
Setup the DMM for mutiple Triggered readings operation.
#in
#in
4032.h"
MM.h"
gRead(int nDmm, int iSettle, int iSamples, int iEdge)
40 for external hardware trigger operation. Following rece
trigger edge of iEd
conjunc n with triggering instruments suc
or greate than iSamp
necessary to read the samples from the DMM using the
DMMReadMeasurement
commun
must keep u
Ohms, IAC, IDC and RTD measurements. Use th
monitor for data availability
Parameter Type/Description
nDmm
iSettle
rements, prior to read value. Must
ecommanded value is 4.
ge polarity of the trigger signal. 1 for Positive, or leading
0 for negative or trailing edge trigger.
Return Value rn valu stants.
int Identifies the DMM. DMMs are numbered starting with zero.
int The number of setteling measu
be set between 0 and 120. R
iSamples
int The number of samples the DMM takes following the same
number of trigger pulses. This number must be between 1 and 250,
inclusive.
iEdge
Int The ed
edge, and
The retu e is one of the following con
Value Meaning
DMM_OKAY
Operation successfully ter
minated
lue
Error code.
Example double Reading[150];
DMMSetTrigRead(0, 4, 150, 0); // Negative edge, 4
//setteling readings, and 150 samples/triggers
for(i=0; i < 150 ; i++) // read buffer
while( ! DMMReadMeasurement(0 , Reading[i]) );
Negative Va