Operator`s manual

51 Signametrics
The following section contains detailed descriptions of each function of the Windows command language. Those
commands that pe only the SM2040 ted. Most functions return an error code. The code can either
be retrieved as a st header file. The
UserDMM.H file pertinen nctions etc. The following description
for the various funct ” funct ions. Keep in mind that the Windows DLL containing
these functions as es to b bit integers (corresponds to VisualBasic long type). TRUE
s –1 and False is 0).
2040 ; SM2042 ;
escription Arm DMM for analog level trigger operation.
204032.h"
int iSamples, double *dThresh)
Remarks VDC, VAC, Ohms, IAC and IDC. Setup the SM2040 for
on. Following reception of this command the DMM makes
value, which exceeds the threshold, dThresh.
as in
the first measurement
The
V range, dThresh must be within -0.330000 and +0.330000. In the
ogTrigger is issued and the time the buffer is read, no other command
uld be sent t xception is the DMMDisArmTrigger command.
Use the DMMR up-
to iSamples, usi
DMMReady re
it prepares the b
r
5.6 Windows Command Language
rtain to are indica
ring using DMMErrString
contains all the
function, or looked up in the SM204032.H
t definitions for the DMM ranges fu
ions is based on “C
sumes all int valu
ion declarat
e windows 32
is 1 and FALSE is 0 (which is also different from VisualBasic where True i
DMMArmAnalogTrigger
2044SM SM ;
D
#include "sm
int DMMArmAnalogTrigger(int nDmm,
This function is usable for
analog level trigger operati
measurements continuously, waiting for a
When this occurs, a trigger is produced with identical processing
DMMArmTrigger. Threshold crossing sense is determined by
following the call of DMMArmAnalogTrigger. If that measurement is lower than the
set threshold, dThresh, subsequent measurements greater than dThresh will trigger the
DMM. If the first measurement is greater than dThresh, subsequent measurements
smaller than dThresh will trigger. For example, if dThresh is 2.00000 V and the first
reading after arming the DMM is 2.500000 V, then 1.999999 V (or smaller) will trigger
the DMM. On the other hand, if dThresh is 1.000000 V and the first reading after
arming the DMM is 0.500000 V, then 1.000001 V (or greater) will trigger the DMM.
dThresh value is in base units, and must be within the DMM range setting. For
example, in the 330 m
33 kΩ, range dThresh must be between 0.0 and 33.0e3.
Following an analog level trigger event, the DMM makes iSamples readings at the set
function, range, and reading rate, and stores them in an internal buffer. Autoranging is
not allowed when using DMMAnalogTrigger. Between the time the
DMMArmAnal
sho o the DMM. One e
eady to monitor when the DMM is ready. When ready, you can read
ng DMMReadBuffer or DMMReadBufferStr functions. Once
turns TRUE, it should not be used again prior to reading the buffer, since
uffer for reading when it detects a ready condition.
Paramete Type/Description
nDmm
iSamples
M takes following a trigger pulse.
nclusive.
og level trigger threshold value
Return Value urn value i
int Identifies the DMM. DMMs are numbered starting with zero.
int The number of samples the DM
This number must be between 1 and 64, i
dThresh
double Anal
The ret s one of the following constants.
Value Meaning