VTI Instruments EX1000A, User Manual

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EX10xxA Programming 99
Despite having the ability to conduct self-calibration at any time, there may be user applications that
require the use of self-calibration, but demand that it create nonvolatile data. The
vtex10xxA_self_cal_store function saves the current self cal data to nonvolatile memory, enabling
it to be loaded upon instrument power cycle and reset. If this function is sent when no current self
cal data is present, an error is generated. Since the existence of nonvolatile self cal data represents
a permanent (although revocable) change from the factory calibration settings, its presence is able
to be ascertained with the
vtex10xxA_self_cal_is_stored query.
Previously saved nonvolatile self cal data can be cleared through the use of the
vtex10xxA_self_cal_clear_stored function. This operation does not clear the current self cal data,
only that in nonvolatile memory. If this function is sent when no nonvolatile self cal data is present,
an error is generated. Alternatively, previously saved nonvolatile self cal data can be loaded as the
current self cal data through the use of the
vtex10xxA_self_cal_load function. If current self cal
data previously existed, it is simply overwritten and need not be cleared in advance. If this function
is sent when no nonvolatile self cal data is present, an error is generated.
The ability to conduct a self-calibration is not affected by the existence of current self cal data or
nonvolatile self cal data. A performed self-calibration will simply overwrite any current self cal data
that already existed. It is not necessary to utilize the
vtex10xxA_self_cal_clear function prior to
performing a new self-calibration. Similarly, the ability to store current self cal data as nonvolatile
is not affected by the existence of previously saved nonvolatile data. The old data is simply
overwritten and need not be cleared in advance.
NOTE As part of the self-calibration process, the EX10xxA is reset, returning all configuration parameters
to their default values.
NOTE Self calibration is not applicable for RX10xx since during factory calibration process each
instrument will be calibrated in precise manner and calibrated data gets stored in the instrument
memory. The instrument has to be sent to factory to perform subsequent calibration after the initial
calibration date is expired.
Refer below section for RX1032 Dynamic Calibration
NOTE EX1044 system requires hard reboot after self-calibration process so that instrument will be
calibrated values gets loaded upon reboot.
Dynamic Calibration in RX1032
The dynamic calibration should be conducted to calibrate the measurement drift due to the
temperature change. For every measurement scan, the values are adjusted based on the system
internal temperature.

The initial calculated Voltage and Temperature coefficients are stored into the RX1032
system.

At every measurement the measured values are calibrated dynamically using the stored
coefficients.

Based on the present temperature of the system, the values are calibrated and reported.
Acquiring a Lock
By default, the EX10xxA allows unrestricted operation from multiple hosts. While this offers a high
level of user flexibility, there are instances where protected operation is desirable, if not required.
For these applications, the EX10xxA can be “locked,” meaning that it will accept functions from
only the host IP address that issued the
vtex10xxA_lock function. With the EX10xxA in this mode,
other host connections that attempt functions will be denied. Self-calibration, in fact, requires the
acquisition of a lock prior to its initiation.