553BTechnical specifications
A.6 Analog signal modules (SMs)
S7-1200 Programmable controller
System Manual, 11/2011, A5E02486680-05
701
Table A- 76 Analog inputs
Model
SM 1231 AI 4 x 13 bit
SM 1231 AI 8 x 13 bit
Number of inputs
4
8
Type
Voltage or current (differential): Selectable in groups of 2
Range
±10 V, ±5 V, ±2.5 V, or 0 to 20 mA
Full scale range (data word)
-27,648 to 27,648
Overshoot/undershoot range
(data word)
Voltage: 32,511 to 27,649 / -27,649 to -32,512
Current: 32,511 to 27,649 / 0 to -4864
Refer to the section on analog input ranges for voltage and current
Overflow/underflow (data word)
Voltage: 32,767 to 32,512 / -32,513 to -32,768
Current: 32,767 to 32,512 / -4865 to -32,768
Refer to the section on input ranges for voltage and current (Page 708).
Resolution
12 bits + sign bit
Maximum withstand voltage/current
±35 V / ±40 mA
Smoothing
None, weak, medium, or strong
Refer to the section on step response times (Page 707).
Noise rejection
400, 60, 50, or 10 Hz
Refer to the section on sample rates (Page 707).
Input impedance
≥ 9 MΩ (voltage) / 280 Ω (current)
Isolation (field side to logic)
None
Accuracy (25°C / 0 to 55°C)
±0.1% / ±0.2% of full scale
Measuring principle
Actual value conversion
Common mode rejection
40 dB, DC to 60 Hz
Operational signal range
Signal plus common mode voltage must be less than +12 V and greater
than -12 V
Cable length (meters)
100 m, twisted and shielded
Table A- 77 Diagnostics
Model
SM 1231 AI 4 x 13 bit
SM 1231 AI 8 x 13 bit
Overflow/underflow
Yes
1
Yes
24 VDC low voltage
Yes
Yes
1
For SM 1231 AI 4 x 13 bit: If a voltage greater than +30 VDC or less than -15 VDC is applied to the input, the resulting
value will be unknown and the corresponding overflow or underflow may not be active.