Measurement Specialties 9116 - Manual (Page 41)

Pressure Systems, Inc. Model 9116 User’s Manual
Page 32 www.PressureSystems.com
Command ‘C’— Sub-command Index 00: Configure & Start Multi-Point Calibration
This sub-command has four (4) additional required parameters used to configure and start the
Multi-Point Calibration function.
Command
“C 00 pppp npts ord avg”
‘C’ is the command letter.
‘ 00’ is the sub-command index (ii) for Configure & Start.
‘ pppp’ is a 1-4 hex digit position field (channel selection bit map), that
selects any of the 1-16 (9116) internal channels to be affected by the
multi-point calibration.
‘ npts’ is the number of unique calibration points (between 1 and 19) to be
supplied during the calibration function.
‘ ord’ is the order of the adjustment fit, which currently must be 1 for a 1st
order linear fit of the calibration data (i.e., a straight line).
‘ avg’ is the number of A/D data samples collected and averaged for each
calibration point supplied (must be a power of 2 in the set 2, 4, 8, 16, or
32)
NOTE: all parameters are separated by a space.
Response
“A”
‘A’ is the acknowledge letter and is returned if all parameters are supplied
with reasonable values. Else, an error (‘N’) response is returned.
Description: Configures and starts the Multi-Point Calibration function. It specifies the
particular channels (pppp) whose offset and span adjustment coefficients will be
replaced when the function is completed. All specified channels must have the
same full-scale pressure range. Modules with more than one range of internal
transducers installed must have channels from each range calibrated separately.
This sub-command immediately alters the module’s normal data acquisition,
processes A/D samples for average count (default = 8, or as per the ‘w10dd’
command), and uses the sub-command’s avg parameter sample count instead.
A larger count (e.g., 32) is encouraged for calibration purposes. The original
sample count will not be restored until the calibration function ends or is aborted
(per other sub-commands described on the following pages).
The npts parameter fixes how many calibration points must be supplied when the
Multi-Point Calibration function’s data collection phase starts later with multiple
invocations of another sub-command (described below). Currently, only a linear
(1st order) (‘ ord=1’) fit of the calibration points is available.