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Temperature Sensor Units Section 7-5
Open-circuit Detection
Function for Temperature
If the circuit is disconnected, the open-circuit detection function will operate
and the converted temperature data will be set to 7FFF.
Open-circuit Detection
Function for Analog
Inputs
The open-circuit detection function is activated when the input range is set to
1 to 5 V and the voltage drops below 0.8 V, or when the input range is set to 4
to 20 mA and the current drops below 3.2 mA. When the open-circuit detec-
tion function is activated, the converted data will be set to 8,000.
The time for enabling or clearing the open-circuit detection function is the
same as the time for converting the data. If the input returns to the convertible
range, the open-circuit detection is cleared automatically and the output
returns to the normal range.
Creating a Ladder
Program
Word Allocations
Temperature Sensor Units are allocated words in the same way as other CP-
series Expansion Units or Expansion I/O Units, in order of connection. A Tem-
perature Sensor Unit is allocated the next input words following the input
words of the CPU Unit or previous Expansion Unit or Expansion I/O Unit. Four
input words are allocated to CP1W-TS003.
Example
Converted Temperature Data
The converted temperature value will be stored in the input words allocated to
the Temperature Sensor Unit in 4-digit hexadecimal.
“m” is the last input word allocated to the CPU Unit, Expansion I/O Unit, or
Expansion Unit connected immediately before the Temperature Sensor Unit.
• Negative values are stored as 2’s complements.
• Data for range codes that include one digit after the decimal point are
stored without the decimal point, i.e., 10 times the actual value is stored.
• If the input temperature exceeds the maximum or minimum value in the
temperature input range that has been set by ±20
°C or ±20°F, the dis-
played value will be held.
• If the circuit is disconnected, the open-circuit detection function will oper-
rate and the converted temperature data will be set to 7FFF.
• The open-circuit detection function will be automatically cleared and nor-
mal input temperature conversion will begin automatically when the input
temperature returns to the convertible range.
Input Data conversion examples
Unit: 0.1°CK or J ×10 500.0°C → 5000 → 1388 hex
−20.0°C → −200 → FF38 hex
−200.0°C → −2000 → F830 hex
None
CP1W-TS003
Temperature Sensor Unit
CP1H
Input word
addresses
Output word
addresses
CIO 0
CIO 1
CIO 100
CIO 101
CIO 2
CIO 3
CIO 4
CIO 5
m+1
Converted temperature data from input 0
m+2
Converted temperature data from input 1
m+3
Converted temperature data from input 2
m+4
Converted temperature data from input 3
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