VXI VT1422A, User Manual

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272 VT1422A Command Reference Chapter 7
CALibration
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The VT1422A's Flash Memory has a finite lifetime of approximately 10,000
write cycles (unlimited read cycles). While executing CAL:STOR once every
day would not exceed the lifetime of the Flash Memory for approximately
27 years, an application that stored constants many times each day would
unnecessarily shorten the Flash Memory's lifetime. See Comments below.
•
Executing CAL:TARE sets the Calibrating bit (bit 0) in Operation Status Group.
Executing CAL:TARE? resets the bit.
•
Because CAL:TARE also performs a *CAL? operation, completion of
CAL:TARE may take many minutes to complete. The actual time it takes the
VT1422A to complete CAL:TARE depends on the mix of SCPs installed.
CAL:TARE performs literally hundreds of measurements of the internal
calibration sources for each channel and must allow seventeen time constants
of settling wait each time a filtered channel's calibrations source value is
changed. The CAL:TARE procedure is internally very sophisticated and results
in an extremely well calibrated module.
•
Any output type channels in <ch_list> are ignored during CAL:TARE.
•
When Accepted: Not while INITiated
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Related Commands: CAL:TARE?, CAL:STOR TARE,
DIAG:CAL:TARE:OTD:MODE
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*RST Condition: Channel offsets are not affected by *RST.
•
Send with VXIplug&play Function: hpe1422_cmd(...)
Command
Sequence
CAL:TARE <ch_list>
to correct channel offsets
CAL:TARE?
to return the success flag from the
CAL:TARE operation
CAL:STORE TARE
Optional depending on necessity of long
term storage
CALibration:TARE:RESet
CALibration:TARE:RESet
resets the tare calibration constants to zero for all
64 channels. Executing CAL:TARE:RES affects the tare cal constants in RAM only.
To reset the tare cal constants in Flash Memory, execute CAL:TARE:RES and then
execute CAL:STORE TARE.
•
Send with VXIplug&play Function: hpe1422_cmd(...)
Command
Sequence
CAL:TARE:RESET
to reset channel offsets
CAL:STORE TARE
Optional if necessary to reset tare cal
constants in Flash Memory.