Measurement Specialties 9116 user manual Calculate and SET Gains Command ‘Z’, Zpppp

Pressure Systems, Inc. Model 9116 User’s Manual

CALCULATE AND SET GAINS (Command ‘Z’)

Purpose: Instructs a module to calculate new gain coefficients, with either full-scalepressure (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-onlycalibration.

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

aposition 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.

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