Pressure Systems, Inc. Model 9116 User’s Manual
Page 31
www.PressureSystems.com
CONFIGURE/CONTROL MULTI-POINT CALIBRATION (Command ‘C’)
Purpose:
This
command
is actually
four (4) sub-commands
. The
first
configures and starts
a
Multi-Point Calibration
adjustment function for selected channels in the
module.
Another
is repeated multiple times to collect data for each defined
calibration point.
Another
ends the calibration function normally by calculating
new
offset
and
gain
adjustment coefficients from the collected data. It then
returns the module to its normal state, but with improved accuracy. A
final
sub-
command is used only if it becomes necessary to
abort
the calibration function
while in progress. The
general form
of all sub-commands is described in the
table below. Subsequent pages separately describe
each individual sub-
command
and give examples of each.
Command
“
C
ii
[
dddd
]...
”
‘C’ is the
command
letter.
‘
ii
’ is a required
sub-command
index preceded by a
space
character.
‘
dddd
’ are zero or more optional
datum
(or parameter) fields, each
preceded by a
space
character. These vary with the sub-command used.
Response
Depends upon the particular sub-command (
ii
) used.
Description:
The four
‘C’
sub-commands configure and control operation of a
Multi-Point
Calibration
function that is similar to the simpler
re-zero
and
span
calibration
adjustment functions (see separate
‘h’
and
‘Z’
commands). However,
‘C’
adjusts
both
the
offset
and
gain
correction coefficients of each affected transducer at the
same time, using two
or more
calibration points. Thus, instead of simply
calculating a new linear (i.e., straight line) adjustment function that
passes
through
the supplied
zero
and
span
calibration points, it calculates a
best-fit
straight line, using the
least squares method,
that
comes “as close as
possible”
to
all
the supplied calibration points
. This correction method
provides the very best adjustment throughout the entire range (negative to
positive) of a differential transducer.
Note
Avoid confusing this Calibrate command ‘C’ (upper case C) with the
Configure/Control Autonomous Host Streams
command ‘c’ (lower
case c).
Like “c,” but unlike most other module commands, all sub-
commands of this command require a
space
between the
command
id
(‘C’) and the first parameter (
ii
).
