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Chapter 8. PROGRAMMING
8 - 4
8
.2.2 A Program for Conversing the Detected Temperature Value(
°
C) into Fahrenheit(
°
F) and
Outputting a BCD Value
1) System Configuration
2) Initial Settings
(1) Specifying used channel : channel 0
(2) Specifying the type of the RTD : Pt 100
3) Expression for Conversing the Detected Temperature Value into a Fahrenheit Temperature
Value(
°
F)
Detected temperature value = real temperature
×
10
Fahrenheit temperature value (
°
F) = real temperature
×
1.8 + 32
= detected temperature value
×
1.8
= detected temperature value
×
18
×
320
∴
If the BCD digital display displays the value of (real Fahrenheit (
°
F) temperature
×
10) then program
has to process the calculation of “detected temperature value
×
18 + 320”.
4) Descriptions of the Program
(1) If P0000 turns on, the RTD input module is initialized.
(2) The detected temperature value is displayed to P0030 to P0043 of the BCD digital display,. If the
value is negative value the ramp P0052 turns on.
(3) The detected temperature value is converted to a Fahrenheit temperature value (
°
F) and displayed
to P0060 to P0073 of the BCD digital display,. If the value is negative the ramp P0050 turns on.
(4) If disconnection is detected during temperature conversion of channel 0, the ramp P0051 turns on.
The lamp turns on if the Fahrenheit
temperature value is a negative value
The Fahrenheit temperature is displayed
(BCD digital display)
10
10
RTD input module
RTD(Pt100)
The lamp turns on disconnection occurs
The lamp turns on if the detected
temperature value is a negative value
+ 32
GM3-
PA1A
GM3-
CPUA
G3I-
D24A
G3F-
RD3A
G3Q-
RY4A
G3Q-
RY2A
G3Q-
RY4A