Scaling Function - Mitsubishi Electric MELSEC iQ-F FX5 User Manual

Scaling function

Performs scale conversion on digital output values within a specified range between a scaling upper limit value and a scaling
lower limit value.
The converted values are stored in 'CH1 Digital operation value' (Un\G402).
Concept of scaling setting
The concepts of each setting item are described below.
• For the scaling upper limit value, set a value corresponding to the upper limit value after the input range conversion.
• For the scaling lower limit value, set a value corresponding to the lower limit value after the input range conversion.
Ex.
If the input range is 0 to 5 V in voltage and the scaling upper and lower limit values are set to 20000 and 4000, respectively,
4000 will be stored in 'CH1 Digital operation value' (Un\G402) when the voltage input is 0 V and 20000 will be stored there
when the voltage input is 5 V.
Calculating the scaling value
The scale value conversion is based on the following formula. (In scale conversion, values are rounded to the nearest whole
number.)
Range setting
Current: 0 to 20 mA, 4 to 20 mA, user range setting
Voltage: 0 to 10 V, 0 to 5 V, 1 to 5 V, user range
setting
Current: -20 to +20 mA
Voltage: -10 to +10 V
If the calculated digital output value is 32767 or more, 32767 will be set. If it is -32768 or smaller, -32768 will
be stored.
Setting procedure
1.
Set "Scaling enable/disable setting" to "Enable".
[Navigation window]  [Parameter]  [Module Information]  Module model name  [Module Parameter] 
[Application setting]  [Scaling function]
2.
Set values for "Scaling upper limit value" and "Scaling lower limit value".
Item
Scaling upper limit value
Scaling lower limit value
• Even when the scaling upper limit value and the scaling lower limit value are set so that the change is
greater than the resolution, the resolution will not increase.
• If the relation between the values is the conversion scaling lower limit value > the conversion scaling upper
limit value, the scale conversion can be performed according to a negative slope.
• Set the scaling with the condition "Scaling upper limit value  Scaling lower limit value".
• When the scaling function is used with the digital clipping function, the scale conversion is performed on the
digital operation values after digital clipping.
1 FX5-4AD
34
1.4 Functions
Relational expression
D × (S - S )
x H L
+ S
L
DMax
D × (S - S ) (S + S )
x H L H L
+
(DMax - DMin) 2
Setting range
-2147483648 to +2147483647 (practical range: -32000 to +32000)
Element
D : Digital output value
x
DMax: Maximum digital output value of the input range in use
DMin: Minimum digital output value of the input range in use
S : Scaling upper limit value
H
S : Scaling lower limit value
L