GE PACSystems RX7i

Chapter 4. Ladder Diagram (LD) Programming
GFK-2950C February 2018 199
4.10.7 Scale
When the SCALE function receives power flow, it scales the
input operand IN and places the result in the output variable
assigned to output operand OUT. The power flow output is
energized when SCALE is performed without Overflow.
Mnemonics:
SCALE_DINT
SCALE_INT
SCALE_DINT
SCALE_UINT
Operands
Parameter
Description
Allowed Operands
Optional
IHI
(Inputs High) Maximum input value (module-related). The
upper limit of the unscaled data. IHI is used with ILO, OHI and
OLO to calculate the scaling factor applied to the input value
IN.
All except S, SA, SB,
SC
No
ILO
(Inputs Low) Minimum input value (module-related). The
lower limit of the unscaled data. Must be the same data type
as IHI.
All except S, SA, SB,
SC
No
OHI
(Outputs High) Maximum output value. The upper limit of the
scaled data. Must be the same data type as IHI. When the IN
input is at the IHI value, the OUT value is the same as the OHI
value.
All except S, SA, SB,
SC
No
OLO
(Outputs Low) Minimum output value. The lower limit of the
scaled data. Must be the same data type as IHI. When the IN
input is at the ILO value, the OUT value is the same as the
OLO value.
All except S, SA, SB,
SC
No
IN
(INput value) The value to be scaled. Must be the same data
type as IHI.
All except S, SA, SB,
SC
No
OUT
(OUTput value) The scaled equivalent of the input value. Must
be the same data type as IHI.
All except S, SA, SB,
SC
No
Example
In the example at right, the registers %R0120 through %R0123 are used
to store the high and low scaling values. The input value to be scaled is
analog input %AI0017. The scaled output data is used to control analog
output %AQ0017. The scaling is performed whenever %I0001 is ON.