NORD Drivesystems BU0550 - Manual (Page 63)

3 AWL (Instruction List, IL)
BU 0550 GB-0813 63
3.5.4 FB_FunctionCurve
This function module produces a mapping control. Defined points can be communicated to the function
block, with which it emulates a function. The output then behaves according to the saved map. Linear
interpolation is carried out between the individual base points.
The base point are defined with X and Y values. The X values are always of the INT type. The Y values can
all be either INT or DINT type, according to the size of the largest base point More memory is occupied if
DINT is used.
The base points are entered in the column "Init Value" in the variables window.
If TRUE is detected at the ENABLE input, the appropriate output value OUTVALUE is calculated on the
basis of the input value INVALUE. VALID indicates that the output value OUTVALUE is valid by means of
TRUE.
As long as VALID is FALSE, the output OUTVALUE has the value 0.
If the input value INVALUE exceeds the upper or lower end of the map, the first or last output value of the
map remains set at the output until INVALUE is once again within the range of the map.. The appropriate
output MINLIMIT or MAXLIMIT is set to TRUE if the map is exceeded or undershot.
ERROR is TRUE, if the abscissa values ( X values) of the map do not increase continuously, or if no table
is initialised. The corresponding error is also output via ERRORID and the output value becomes 0. The
error is reset if ENABLE = FALSE.
Table 89 FB_FunctionCurve
VAR_INPUT VAR_OUTPUT
Input Explanation Type Output Explanation Type
ENABLE Execute BOOL VALID Output value is valid BOOL
INVALUE Input value ( x ) INT ERROR Error in FB BOOL
ERRORID Error code INT
MAXLIMIT Maximum limit reached BOOL
MINLIMIT Minimum limit reached BOOL
OUTVALUE Output value ( y ) DINT
ERRORID Explanation
0 No error
1400h Abscissa values (X values) of the map not always increasing
1401h No map initialised