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.
