SM 1231 analog input module specifications

S7-1200 Programmable controller

ft:publication_title
S7-1200 Programmable controller
Product
S7-1200
Version
V20
Publication date
11/2024
Language
en-US
Version
20
Table 1. General specifications

Model

SM 1231 AI 4 x 13 bit

SM 1231 AI 8 x 13 bit

SM 1231 AI 4 x 16 bit

Article number

6ES7231-4HD32-0XB0

6ES7231-4HF32-0XB0

6ES7231-5ND32-0XB0

Dimensions W x H x D (mm)

45 x 100 x 75

Weight

180 grams

Power dissipation

2.2 W

2.3 W

2.0 W

Current consumption (SM Bus)

80 mA

90 mA

80 mA

Current consumption (24 V DC)

45 mA

60 mA

65 mA

Table 2. Analog inputs

Model

SM 1231 AI 4 x 13 bit

SM 1231 AI 8 x 13 bit

SM 1231 AI 4 x 16 bit

Number of inputs

4

8

4

Type

Voltage or current (differential): Selectable in groups of 2

Voltage or current (differential)

Range

±10 V, ±5 V, ±2.5 V, 0 to 20 mA, or 4 mA to 20 mA

±10 V, ±5 V, ±2.5 V, ±1.25 V, 0 to 20 mA or 4 mA to 20 mA

Full scale range (data word)

-27648 to 27648 voltage / 0 to 27648 current

Overshoot/undershoot range

(data word)

Refer to the section on analog input ranges for voltage and current.

Voltage: 32511 to 27649 / -27649 to -32,512

Current: 32511 to 27649 / 0 to -4864

Overflow/underflow (data word)

Refer to the section on input ranges for voltage and current .

Voltage: 32767 to 32512 / -32513 to -32768

Current 0 to 20 mA: 32767 to 32512 / -4865 to -32768

Current 4 to 20 mA: 32767 to 32512 (values below -4864 indicate open wire)

Resolution1

12 bits + sign bit

15 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.

Noise rejection

400, 60, 50, or 10 Hz

Refer to the section on sample rates.

Input impedance

Before parameterization

Voltage

Current

≥ 1 MΩ

≥ 9 MΩ, FS 06 and above ≥ 1 MΩ

≥ 270 Ω, < 290 Ω

≥ 1 MΩ

≥ 1 MΩ

< 315 Ω, > 280 Ω

Isolation

Field side to logic

Logic to 24 V DC

Field side to 24 V DC

Channel to channel

None

707 V DC (type test)

707 V DC (type test)

500 V DC (type test)

None

Accuracy (25 °C / -20 to 60 °C)

±0.1% / ±0.2% of full scale

±0.1% / ±0.3% of full scale

Measuring principle

Actual value conversion

 

Common mode rejection

40 dB, DC to 60 Hz

Operational signal range1

Signal plus common mode voltage must be less than +12 V and greater than -12 V

Cable length (meters)

100 m, twisted and shielded

1 Voltages outside the operational range applied to one channel may cause interference on other channels.

Table 3. Diagnostics

Model

SM 1231 AI 4 x 13 bit

SM 1231 AI 8 x 13 bit

SM 1231 AI 4 x 16 bit

Overflow/underflow

Yes

24 V DC low voltage

Yes

Open wire

4 to 20 mA range only (if input is below -4864; 1.185 mA)