Measurement Specialties 9116 user manual CONFIGURE/CONTROL MULTI-POINT Calibration Command ‘C’

Pressure Systems, Inc. Model 9116 User’s Manual

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-commandindex 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-zeroand 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-fitstraight 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).

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