Scaling Function - Mitsubishi Electric MELSEC iQ-R User Manual

1.6

Scaling Function

High speed Medium speed
This function performs the scale conversion on digital output values. The values are converted within a specified range
between a scaling upper limit value and scaling lower limit value. This function reduces the time and effort to create a program
of the scale conversion.
The converted values are stored in 'CH1 Digital operation value' (Un\G402).
Concept of scaling setting
Ex.
When the input range is set to -10 to 10V:
For the scaling lower limit value, set a value corresponding to the lower limit value of the input range (-32000).
For the scaling upper limit value, set a value corresponding to the upper limit value of the input range (32000).
Calculating the scaling value
The scale conversion is based on the following formula. (In the scale conversion, values are rounded to the nearest whole
number.)
• Current: 0 to 20mA, 4 to 20mA, 4 to 20mA (extended mode)
• Voltage: 0 to 10V, 0 to 5V, 1 to 5V, 1 to 5V (extended mode)
D × (S - S )
X H L
D =
+ S
Y
L
D
Max
• Voltage: -10 to 10V
D × (S - S ) (S
X H L H
D =
+
Y
D - D 2
Max Min
D : Digital output value
X
D : Scaling value (Digital operation value)
Y
D : Maximum digital output value of the input range in use
Max
D : Minimum digital output value of the input range in use
Min
S : Scaling upper limit value
H
S : Scaling lower limit value
L
*1 Although the range of the digital output value in the extended mode is -8000 to 32000, this function performs the scale conversion on
digital output values within the range of 0 to 32000.
Setting procedure
1.
Set "Scaling enable/disable setting" to "Enable".
[Navigation window]  [Parameter]  [Module Information]  Module model name  [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 scaling lower limit value > 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".
Low speed
+ S )
L
*1
, user range setting (current)
*1
, user range setting (voltage)
Setting range
-32000 to 32000
1 FUNCTIONS
39
1.6 Scaling Function
1