Pressure Systems, Inc. Model 9116 User’s Manual
Page 41
www.PressureSystems.com
CALCULATE AND SET GAINS (Command ‘Z’)
Purpose:
Instructs a module to calculate new
gain
coefficients, with either
full-scale
pressure (or a
specified
pressure) applied to the specified channels. These new
coefficients update part of the module’s internal calibration coefficient database,
used to convert any subsequent raw data (from any of the specified channels)
into engineering units data. The new gain values are also returned in the
response. This command is sometimes called a
Span or Span-only
calibration.
Command
“
Z
pppp
[
vv.vvvv
]
”
‘Z’ is the
command
letter
‘
pppp
’ is the
position
field
‘
vv.vvvv
’ is an [optional]
pressure
value, preceded by a
space
character
.
Response
“
g.gggg .. g.gggg
”
‘
g.gggg
’ are the actual
gain
data values returned, each preceded by a
space
.
Description:
The
position
field may have 0 or 4 characters. If no
position
field is specified,
gain
coefficients for all module input channels will be calculated and returned. If
a
position
field is specified,
gain
coefficients for only the channels whose bits are
set (=1) will be calculated and returned. If the optional
pressure
value (
vv.vvvv
)
is specified, the
position
field must be 4 characters, even when all channels are
to be specified.
Gain
values are returned in the response in order of
highest
specified channel to
lowest
specified channel, with data formatted per an
implied
decimal format (
f
=0).
Normally this command requires that the
exact full scale
input pressure be
applied to the affected channels. The optional
pressure
value [
vv.vvvv
] allows
the user to specify
any suitable upscale pressure
in the current engineering units.
For best results, pressures in excess of 90% of full scale should be applied. A
leading
space
character must precede the
pressure
value parameter.
The desired calibrating pressure must be applied to all of the specified channels
and allowed to stabilize before this command is executed. Such a pressure is
presumably generated by a separate model 903x calibrator module or suitable
user-supplied substitute.
Notice that unlike the
Calculate and Set Offsets
(‘h’)
command, this command
does not automatically move a
Model 9116
module’s calibration valve to its Cal
position. A command to do this must precede this command. The reader is
referred to
Chapter 4, Section 4.3
for additional details concerning the
performance of a Span Calibration.
