Pressure Systems 98RK-1 - Manual (Page 56)

Pressure Systems, Inc. 98RK-1 & 9816 User’s Manual©
Page 54 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 internal 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 Gain 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 internal module channels (16-1) 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).
NOTE: This command may only be applied to the sixteen (16) internal channels.
It is not applicable for the external 98RK-1’s purge/supply (P & S) channels.
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.
Internal 9816 firmware limits the allowed values for the calculated gain
coefficients between 0 and 100. If internal calculations result in gain coefficients
outside of this range, a default value of 1.00 will be used.
Notice that unlike the Calculate and Set Offsets (‘h’) command, this command
does not automatically move the 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.