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CHAPTER 4 FUNCTIONS
4
4.11 Temperature Process Value (PV) Scaling Function
(a) Calculation example
A calculation example to scale the temperature process value (PV) into percentage is shown below.
Set the following buffer memory areas as below.
•CH Input range (Un\G32, Un\G64, Un\G96, Un\G128): 38 (Temperature measurement range: -200.0°C
to 400.0°C)
•CH Process value (PV) scaling lower limit value (Un\G726, Un\G742, Un\G758, Un\G774): 0
•CH Process value (PV) scaling upper limit value (Un\G727, Un\G743, Un\G759, Un\G775): 100
Suppose that 3600 (360.0°C) is stored in CH Temperature process value (PV) (Un\G9 to Un\G12).
The scaling value can be calculated as follows:
(3) Setting method
Set buffer memory areas in the following procedure.
1. Enable or disable the temperature process value (PV) scaling function in the following buffer
memory area.
CH Process value (PV) scaling function enable/disable setting (Un\G725, Un\G741, Un\G757,
Un\G773) ( Page 152, Section 3.4.2 (76))
2. Set a scaling upper limit value and lower limit value in the following buffer memory areas.
● An error does not occur even though the areas above are set as follows: Lower limit value Upper limit value. The
scaling is processed according to the calculation method described on Page 192, Section 4.11 (2).
● If a value outside the temperature measurement range is measured, the value set as a upper limit or lower limit is stored
into the following buffer memory area.
•CH Process value (PV) scaling value (Un\G728, Un\G744, Un\G760, Un\G776) ( Page 153, Section 3.4.2
(78))
Buffer memory area name
Buffer memory address
Reference
CH1 CH2 CH3 CH4
CH Process value (PV) scaling lower
limit value
Un\G726 Un\G742 Un\G758 Un\G774
Page 153, Section 3.4.2 (77)
CH Process value (PV) scaling upper
limit value
Un\G727 Un\G743 Un\G759 Un\G775
=
=
=
+
(100 - 0)
93.333
93 (All decimal places are rounded off to an integer.)
(3600 - (-2000))
4000 - (-2000)
0
CH Process value (PV) scaling value
(Un\G728, Un\G744, Un\G760, Un\G776)