Siemens SIMATIC S7 System Manual page 761

Table A- 128 Resistance
Range Under range
minimum
150 Ω n/a
300 Ω n/a
600 Ω n/a
Resistance values above the over-range minimum value are reported as +32767.
1
Note
The module reports 32767 on any activated channel with no sensor connected. If open wire
detection is also enabled, the module flashes the appropriate red LEDs.
When 500 Ω and 1000 Ω RTD ranges are used with other lower value resistors, the error
may increase to two times the specified error.
Best accuracy will be achieved for the 10 Ω RTD ranges if 4 wire connections are used.
The resistance of the connection wires in 2 wire mode will cause an error in the sensor
reading and therefore accuracy is not guaranteed.
Table A- 129 Noise reduction and update times for the RTD module
Rejection frequency selection
400 Hz (2.5 ms)
60 Hz (16.6 ms)
50 Hz (20 ms)
10 Hz (100 ms)
To maintain module resolution and accuracy when the 400 Hz filter is selected, the integration time is 10 ms. This selec-
1
tion also rejects 100 Hz and 200 Hz noise.
Note
After power is applied, the module performs internal calibration for the analog-to-digital
converter. During this time the module reports a value of 32767 on each channel until valid
data is available on that channel. Your user program may need to allow for this initialization
time. Because the configuration of the module can vary the length of the initialization time,
you should verify the behavior or the module in your configuration. If required, you can
include logic in your user program to accommodate the initialization time of the module.
S7-200 SMART
System Manual, V2.3, 07/2017, A5E03822230-AF
Nominal range Nominal range
low limit high limit
0 (0 Ω) 27648 (150 Ω)
0 (0 Ω) 27648 (300 Ω)
0 (0 Ω) 27648 (600 Ω)
Integration time
10 ms
16.67 ms
20 ms
100 ms
A.5 Thermocouple and RTD expansion modules (EMs)
Over range
maximum
1
176.383 Ω
352.767 Ω
705.534 Ω
4-/2-wire: 0.142
1
3-wire: 0.285
4-/2-wire: 0.222
3-wire: 0.445
4-/2-wire: 0.262
3-wire: .505
4-/2-wire: 1.222
3-wire: 2.445
Technical specifications
Normal range Normal range
accuracy @ 25 accuracy -20
°C °C to 60°C
±0.05% ±0.1%
±0.05% ±0.1%
±0.05% ±0.1%
Update time (seconds)
761