WAGO-I/O-SYSTEM 750
Process Image 33
750-450 4 AI RTD
Manual
Version 1.2.0
4.3.2
Pt100 (IEC 751), ID 0
4.3.2.1 Standard Format
The "Pt100 (IEC 751)" setting is used by the I/O module to convert the resistance
measured values from Pt100 sensors (IEC 751) to temperature values and
outputs the results in degrees Celsius.
The temperature values are displayed with a resolution of 1 digit per 0.1 °C in
one word (16 bits). Temperature values below 0 °C are represented in two's
complement binary. As a result, 0°C corresponds to the numeric value 0x0000
and 100°C to 0x03E8 (dec. 1000).
The maximum numeric range in the two's complement representation that can be
displayed with one word ranges from −32768 to +32767. The numeric range that
is used depends on the set sensor type and on the resolution for the process
value. With the "Pt100 (IEC 751)" setting, the possible numeric range
corresponds to the temperature range of −200 °C to +850 °C, meaning it covers
a range of −2000 to +8500.
Table 26: ID 0, Pt100 Setting (IEC 751), Standard Format
Temperature
°C
Resistance
Ω
Numeric value
1)
Status
byte
hex.
Error
LED
Binary
Hex.
Dec.
---
< 10.00
'1111.1000.0011.0000'
0xF830
−2000
0x50
ON
Short circuit
2)
< –200.0
< 18.52
'1111.1000.0011.0000'
0xF830
−2000
0x41
ON
Underrange
3)
−200.0
18.52
'1111.1000.0011.0000'
0xF830
−2000
0x00
OFF
−100.0
60.256
'1111.1100.0001.1000'
0xFC18
−1000
0x00
OFF
0.0
100.00
'0000.0000.0000.0000'
0x0000
0
0x00
OFF
100.0
138.506
'0000.0011.1110.1000'
0x03E8
1000
0x00
OFF
200.0
175.856
'0000.0111.1101.0000'
0x07D0
2000
0x00
OFF
500.0
280.978
'0001.0011.1000.1000'
0x1388
5000
0x00
OFF
750.0
360.638
'0001.1101.0100.1100'
0x1D4C
7500
0x00
OFF
800.0
375.704
'0001.1111.0100.0000'
0x1F40
8000
0x00
OFF
850.0
390.481
'0010.0001.0011.0100'
0x2134
8500
0x00
OFF
> 850.0
> 390.481
'0010.0001.0011.0100'
0x2134
8500
0x42
ON
Overrange
3)
---
> 5010.00
'0010.0001.0011.0100'
0x2134
8500
0x60
ON
Wire break
2)
1) Temperature values below 0 °C are represented in two's complement binary.
2) When short circuit and wire break monitoring is on (see Section "Diagnostics" > "Error
Response")
3) When lower/upper limit violation detection is on (see Section "Diagnostics" > "Error Response")