Operator`s manual

Signametrics 46
ers such as DMM type (SM2040/42/44), and
at are the names of these files. A qualified technician may modify individual entries in the calibration
r
and, you
ill need to convert the SM204032.DEF and SM204032.LIB using ImpDef.exe and ImpLib.exe, provided with
e
the
wo functions are provided to return DMM readings. DMMRead returns the next reading as a scaled double-
prec ing as a formatted string ready to be displayed.
by
ich
Multiple Card Operations Under Windows
During initialization (DMMInit()), the driver reads various paramet
serial number, and then reads the corresponding calibration information from the SM40CAL.DAT file.
The DMMInit() function reads the information from these files to initialize the DMM. DMMInit accepts
arameters th
p
file, then reload them using the DMMLoadCalFile command.
5.2 Using the SM2040 Driver With C++ or Similar Software
Install the SM204032.H and UserDMM.H header file in a directory that will be searched by your C/C++ compile
for header files. This header file is known to work with Microsoft Visual C++™. To compile using Borl
w
the compiler. Install SM204032.LIB in a directory that will be searched by the linker for import libraries. Th
SM2040 software must be installed prior to running any executable code. Install the SM204032.DLL in a location
where either your program will do a LoadLibrary call to load it, or on the PATH so that Windows will load
DLL automatically.
In using the SM2040 driver, first call DMMInit to read the calibration information. Call DMMSetFunction to set
the DMM function. The DMM function constants are defined in the UserDMM.H header file, and have names that
clearly indicate the function they invoke. Use DMMSetRate to set the reading rate defined in the header file.
T
ision (double) result, and DMMReadStr returns the next read
All functions accept a DMM-number parameter, which must be set to the value nDmm, which was returned
DMMInit() function. For multiple DMMs, this value will be 0,1,2.. n. Most functions return an error code, wh
an be retrieved as a string using DMMErrStr().
c
Single .EXE operation
Acc g the
Win e
.EX
initi to be
accessed. Since this configuration utilizes the DLL to service all DMMs, it must handle a single reading or control
com le, when one DMM reads DCV, and another reads Capacitance, the DLL must
finish reading the DCV before it will proceed to take a Capacitance reading. Being a relatively slow measurement,
Cap urement throughput. For improved performance, one can use the following:
ration
essing multiple DMMs from a single executable is the most common way for running up to 10 DMMs usin
dows DLL. A combination of several SM2040s, SM2042s and SM2044s can be controlled, as long as the singl
E (Thread) is used to control all of the units. Make sure that prior to issuing commands to any DMM, it is
alized using DMMInit(). The nDmm parameter is passed with each DLL command to define the DMM
mand one at a time. For examp
acitance will dictate the meas
Multiple .EXE ope
By having several copies of SM204032.DLL, and renaming them, you can run multiple DMMs with separate
exec ng a copy named SM204032A.DLL in C:\windows\system (Win98/95), and having
two 0.exe and MultiExe1.exe, each of the executables will run independently, making
calls is can provide an execution throughput advantage over the method mentioned above.
If us Exe.exe source code should define nDmm = 0, and MultiExe1.exe should define
nDmm = 1. Also the first should declare the SM204032.DLL and the second should declare SM204432.DLL:
clarations:
"sm204032.dll" (ByVal calFile As String) As Long
Val nDmm As Long, dResult As Double) As Long
MultiExe1.exe VB function declarations:
32A.dll" (ByVal calFile As String) As Long
Declare Function DMMRead Lib "sm20432A.dll" (ByVal nDmm As Long, dResult As Double) As Long
/**** ***** ********
utables. For instance, havi
MultiExe
executable files,
to the respective DLL. Th
ing VisualBasic, the Multi
MultiExe0.exe VB function de
Declare Function DMMInit Lib
Declare Function DMMRead Lib "sm204032.dll" (By
NDmm = 0
Declare Function DMMInit Lib "sm204
NDmm = 1
****************** ** ******************************* ***