27
Signametrics
DMMCalibrate
Description
Internally calibrate the DMM.
#include "SM2060.h"
int
DMMCalibrate
(
int nDmm
)
Remarks
This function performs self calibration of the various components of the DMM, as well
as an extensive self test. At the end of this operation it returns the DMM to the current
operating mode. Using this function periodically, or when the DMM internal temperature
varies, will enhance the accuracy of the DMM. Using this function does not remove the
requirement to perform periodic external calibration.
Parameter
Type/Description
nDmm
int
Identifies the DMM. DMMs are numbered starting with zero.
Return Value
The return value is one of the following constants.
Value
Meaning
DMM_OKAY
DMM is OK.
Negative Value
Error
Example
status = DMMCalibrate(0); /* a quick internal cal.*/
Comments
This performs an internal DMM calibration and is the same as the
S-Cal
command in the
VB Control Panel. It is not related to the external calibration represented in the
SM60CAL.DAT
file.
DMMCleanRelay
Description
Service function that cleans specified relay.
#include "SM2060.h"
int
DMMCleanRelay(int
nDmm, int iRelay, int iCycles)
Remarks
This function cleans
iRelay
by vibrating the contact
iCycles
times. This function is useful
for removing oxides and other deposits from the relay contacts. DC Current
measurements are particularly sensitive to K2 contact resistance and therefore should be
cleaned periodically. It is also useful for making sound in computer without a speaker.
Parameter
Type/Description
iRelay
int
The relay to clean. 1 for K2, 2 for K2 and 3 for K3.
iCycles
int
The number of times the relay contact is shaken. 1 to 1000.
nDmm
int
Identifies the DMM. DMMs are numbered starting with zero.
Return Value
Integer error code..
