FB_HVACScaleXX

Characteristic curves with 2, 4 or 7 interpolation points can be mapped with the function blocks FB_HVACScale02, FB_HVACScale04 and FB_HVACScale07 (shown here). The analog raw value is applied to the input IrX and output as the calculated Y value at the output IrY. Different slopes of the characteristic curve can be specified in sections by specifying various interpolation points. The range is limited internally to the values lrY01 and lrY07 with the aid of the input bLmt.

VAR_INPUT

lrX   : LREAL;
lrX0n : LREAL;
lrY0n : LREAL;
bLmt  : BOOL;

lrX: Applied raw value.

lrX0n: X interpolation point of the characteristic curve. The characteristic curve has 2, 4 or 7 interpolation points, depending on the scaling function block.

lrY0n: X interpolation point of the characteristic curve. The characteristic curve has 2, 4 or 7 interpolation points, depending on the scaling function block.

bLmt: Input for limiting the output Y-range to values between lrY01 and lrY0n, depending on the maximum number of interpolation points.

VAR_OUTPUT

lrY              : LREAL;
bError           : BOOL;
eErrorCode       : E_HVACErrorCodes;
udiErrorArgument : UDINT;

lrY: Calculated Y-value of the characteristic curve.
bError: Incorrect entry of the X interpolation points. The values must be entered in ascending order. No two X-values may be the same.
eErrorCode: The error message eHVACErrorCodes_ErrIdlrX0x will be displayed.
udiErrorArgument: Indication of which interpolation point has been entered incorrectly.

Requirements