Operator`s manual

79 Signametrics
Read
SM ; SM2044 ;
M for ready status, and returns the next floating-point reading.
int nDmm, double FAR *lpdResult)
If the DMM is not ready it will return
Parame
DMMPolled
2040 ; SM2040
Description Tests the DM
#include "sm204032.h"
DMMPolledRead(int
Remarks DMMPolledRead polls the DMM for readiness.
FALSE. If the DMM is ready with a new reading it will return TRUE, and the reading
will be placed at the location pointed to by lpdResult. See DMMPolledReadCmd for
more details. Do not use DMMReady to check for readiness since it will cause
communication failure.
ter
Type/Description
nDmm
starting with zero.
ints to the location to hold the next reading.
Return Value The return valu
int Identifies the DMM. DMMs are numbered
lpdResult
double FAR * Po
e is one of the following constants.
Value Meaning
FALSE
eady, and reading is placed at lpdResult
Example
read;
// Show
PolledRe
SM2040 ; SM2042 ;
Des MM Polled Read command.
204032.h"
Remarks ith a prior Polled read process, this function will trigger the
st be set to a specific range and
mand: VDC, VAC, IDC, IAC,
2-wire, 4-wire, 6-wire, or RTD function. Composite functions such as Capacitance,
Inductance, Peak-to-Peak etc. are not capable of polled read operation. Measurement rate
must be 10 rps or higher. If FALSE is returned, the DMM is busy processing a prior
polled read. A DMM_OKAY indicates the DMM accepted the read command and
entered the busy state. The DMM remains busy until it is ready with the next reading.
This function is useful where it is necessary to conserve CPU time and make the DMM a
polled device. Use DMMPolledRead or DMMPolledReadStr to test for readiness and
read measurement. Do not use DMMReady to check for readiness since it will cause
communication failure.
DMM is not ready
TRUE
DMM is r
Negative Value
Error code
double
if(DMMPolledRead(0, &d)) fprintf(“%9.4f\n”,d);
DMM adCmd
SM2044 ;
cription Send D
#include "sm
int DMMPolledReadCmd(int nDmm)
If the DMM is not busy w
DMM to execute a single read command. The DMM mu
one of the following functions to use the polled read com