Pressure Systems 98RK-1 user manual Command “C 00 pppp npts ord avg”

Pressure Systems, Inc. 98RK-1 & 9816 User’s Manual©

Command 'C'— Sub-command Index 00: Configure & Start Multi-Point Calibration

This sub-command has four (4) additional required parameters used to configure and start the Multi-Point Calibration function.

Command “C 00 pppp npts ord avg”

‘C’ is the command letter.

‘00’ is the sub-command index (ii) for Configure & Start.

‘pppp’ is a 1-4 hex digit position field (channel selection bit map), that selects any of the 1-16 internal channels to be affected by the multi-point calibration. It cannot specify external channels P & S.

‘npts’ is the number of unique calibration points (between 1 and 19) to be supplied during the calibration function.

‘ord’ is the order of the adjustment fit, which currently must be 1 for a 1st order linear fit of the calibration data (i.e., a straight line).

‘avg’ is the number of A/D data samples collected and averaged for each calibration point supplied (must be a power of 2 in the set 2, 4, 8, 16, 32, or 64)

NOTE: all parameters are separated by a space.

Response “A”

‘A’ is the acknowledge letter and is returned if all parameters are supplied with reasonable values. Else, an error (‘N’) response is returned.

Description: Configures and starts the Multi-Point Calibration function. It specifies the particular channels (pppp) whose offset and span adjustment coefficients will be replaced when the function is completed. All specified channels must have the same full-scale pressure range. Modules with more than one range of internal transducers installed must have channels from each range calibrated separately.

This sub-command immediately alters the module’s normal data acquisition process’s A/D samples for average count (default = 8, or as per the ‘w10dd’ command) and uses the sub-command’s avg parameter sample count instead. A larger count (e.g., 64) is encouraged for calibration purposes. The original sample count will not be restored until the calibration function ends or is aborted (per other sub-commands described on the following pages).

The npts parameter fixes how many calibration points must be supplied when the Multi-Point Calibration function’s data collection phase starts later with multiple invocations of another sub-command (described below). Currently, only a linear (1st order) fit of the calibration points is available.

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