Measurement Specialties 9116 - Manual (Page 50)

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
“Zpppp[ 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.