VTI Instruments Corp.
222
EX1629 Command Set
vtex1629_self_cal_init
F
UNCTION
P
ROTOTYPE
ViStatus vtex1629_self_cal_init (ViSession
vi
, ViPInt32
overRide
, ViPInt32
recommendedUpTime
, ViPInt32
currentUpTime
);
F
UNCTION
P
ARAMETERS
vi
= contains a session handle to the instrument. This handle is obtained by the function and remains valid until the
session is closed.
overRide
= a returned integer value indicating the override value.
recommendedUpTime
= an integer return value indicating the number of seconds recommended for having the box
powered on before attempting a self-calibration.
currentUpTime
= an integer return value indicating the number of seconds that the unit has been powered up.
D
ATA
I
TEM
R
ESET
V
ALUE
Not applicable to this function.
D
ESCRIPTION
This function initializes the self-calibration routine on the EX1629. Note that the device should be left on and
undisturbed throughout the entire calibration process. To check the progress of the calibration routine, refer to the
vtex1629_self_cal_get_status function.
NOTE
The self-calibration uptime requirement is in place to protect the measurement integrity of the
instrument. Overriding the requirement must only be done when the operating conditions allow it.
An example of this is where the unit has actually been warmed up, but has simply been subjected
to a quick power cycle or reboot. In order to ensure that the override is intentional, it is strongly
recommended that user intervention be required in the software application to employ it.
The
overRide
parameter is used in the case where a self-calibration is attempted on a unit that has not been powered
on for a sufficient amount of time. In this special case, the first call to this function will return an error, but will also
populate this override variable with a unique integer value. The vtex1629_self_cal_init
function can then be called a
second time using this unique value. The second call to the function will successfully initiate a self-calibration on a
unit that has not been powered up for the recommended duration of time.
Because it modifies the system configuration, an instrument synch (vtex1629_soft_synch) will be required before
continuing with other operations.
NOTE
In order to perform a self-calibration, a lock on the instrument must first be acquired. Attempting
to self-calibrate without the acquisition of a lock will generate an error that is not able to be
overridden. See the vtex1629_lock function.
NOTE
Additional instrument driver calls, other than vtex1629_self_cal_get_status, should not be
performed until the result of
calStatus
in the vtex1629_self_cal_get_status call is equal to
VTEX1629_SELF_CAL_COMPLETE.
E
XAMPLE
ViSession instrumentHandle;
ViStatus status;
ViInt32 ovrride, rec_uptime, act_uptime;
ViBoolean okay_to_override = VI_FALSE;
…
status = vtex1629_self_cal_init (instrumentHandle,
&override,
&rec_uptime,
&act_uptime);
if (status >= VI_SUCCESS) {
