Programming Technique
Chapter 25
25-6
Figure 25.6
Converting Temperature Values
200
100
X
202
000
G
201
009
G
X
203
900
203
900
:
205
180.000
G
204
005
G
206
:
205
180
212
G
207
032
G
210
+
210
212
1.0
G
211
190
G
033
TON
PR 003
AC 000
033
15
15
011
033
17
PR 999
034
CTU
AC 000
210
212
16
G
220
212
=
011
L
110
14
16
011
U
Suppose that you connected a thermocouple to an input module that
measures Celsius temperature. A block transfer read transfers the
temperature into the processor’s data table.
For your ease, you would like to convert the recorded Celsius temperature
in the data table to Fahrenheit values for display. This temperature must
maintain certain range values for your application. You would like to:
monitor the temperature from 87 to 100
o
C
count the times the value falls below 190
o
F
count the times the values stay at 212
o
F
Formula:
o
F = (9/5) x
o
(C) + 32
In this example, the value read into the data table at address 200 is 100
o
C .
