Programmable Logic Controller Guide: Selection, Application, and Maintenance for Engineers
PLC selection guide for engineers covering IEC 61131 compliance, Siemens, Rockwell, Schneider, ABB comparison, scan time sizing, and wiring. Shop at Stoklink.
- Part number
- 6ES7221-1BF32-0XB0
- Model no
- SM 1221, DI 8x24 V DC
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· From Türkiye
0
- CE
- UL
SIMATIC S7-1200Siemens 6ES7221-1BF32-0XB0 SIMATIC S7-1200 SM 1221 8DI 24V DC Digital Input Module
SIMATIC S7-1200 SM 1221 digital input module: 8DI, 24V DC, sink/source, IEC 61131 type 1, IP20, 45mm wide.
Description
About the SM 1221, DI 8x24 V DC
About the SM 1221, DI 8x24 V DC
The Siemens 6ES7221-1BF32-0XB0 is a SIMATIC S7-1200 SM 1221 digital input module with 8 sink/source inputs at 24 V DC, in groups of 2. Input delay is parameterizable from 0.2 to 12.8 ms per IEC 61131 type 1. It draws up to 105 mA from the backplane bus, reports diagnostic alarms, and mounts in a 45 mm wide housing rated IP20.
Certifications & Standards
- CE
- CSA
- UL
- cULus
- FM
- RCM
- KC
- Marine
Selection Notes
8 sink/source-configurable inputs in groups of 2 let this module mix PNP and NPN field devices on the same S7-1200 station without separate sourcing/sinking modules. Input delay is parameterizable per group from 0.2 to 12.8 ms, so fast digital inputs used for interrupts can run at the low end while noisy limit-switch wiring uses a longer filter time on the same module. At 45 mm width it's one of the wider S7-1200 signal modules — where panel space is tight, an equivalent SM 1221 with fewer channels in a narrower housing is worth checking.
Applications
Fits small S7-1200 machine controllers reading discrete sensors, limit switches and pushbuttons where sink/source flexibility is needed on the same module.
Specification
Full specification
General information 1
| Product type designation | SM 1221, DI 8x24 V DC |
|---|
Supply voltage 3
| Rated value (DC) | 24 V |
|---|---|
| permissible range, lower limit (DC) | 20.4 V |
| permissible range, upper limit (DC) | 28.8 V |
Input current 2
| from backplane bus 5 V DC, max. | 105 mA |
|---|---|
| Digital inputs: from load voltage L+ (without load), max. | 4 mA; per channel |
Show all 71 specifications ↓ Show less ↑65 more values in Identification, Output voltage, Power loss, Digital inputs, Interrupts/diagnostics/status information, Potential separation, Degree and class of protection, Standards, approvals, certificates, Ambient conditions, Connection method, Mechanics/material, Version Classification, Logistics.
Identification 10
| Part number | 6ES7221-1BF32-0XB0 |
|---|---|
| Type designation | SM 1221, DI 8x24 V DC |
| Brand | Siemens |
| Condition | New, factory sealed |
| Source | Siemens and its authorised distributors |
| Warranty | Manufacturer warranty |
| Lifecycle status | Active, in production |
| EAN | 6940408101913 |
| ETIM class | EC001419 |
| eCl@ss | 27242204 |
Output voltage 1
| Power supply to the transmitters: present | Yes |
|---|
Power loss 1
| Power loss, typ. | 1.5 W |
|---|
Digital inputs 13
| Number of digital inputs | 8 |
|---|---|
| in groups of | 2 |
| Input characteristic curve in accordance with IEC 61131, type 1 | Yes |
| Number of simultaneously controllable inputs all mounting positions: up to 40 °C, max. horizontal installation | 8 |
| Input voltage: Rated value (DC) | 24 V |
| Input voltage: for signal "0" | 5 V DC at 1 mA |
| Input voltage: for signal "1" | 15 V DC at 2.5 mA |
| Input current: for signal "0", max. (permissible quiescent current) | 1 mA |
| Input current: for signal "1", min. | 2.5 mA |
| Input current: for signal "1", typ. | 4 mA |
| Input delay (for rated value of input voltage) for standard inputs: parameterizable for interrupt inputs | Yes; 0.2 ms, 0.4 ms, 0.8 ms, 1.6 ms, 3.2 ms, 6.4 ms and 12.8 ms, selectable in groups of four |
| Cable length: shielded, max. | 500 m |
| Cable length: unshielded, max. | 300 m |
Interrupts/diagnostics/status information 2
| Alarms: Diagnostic alarm | Yes |
|---|---|
| Diagnostics indication LED: for status of the inputs | Yes |
Potential separation 1
| Potential separation digital inputs: between the channels, in groups of | 2 |
|---|
Degree and class of protection 1
| IP degree of protection | IP20 |
|---|
Standards, approvals, certificates 13
| CE mark | Yes |
|---|---|
| CSA approval | Yes |
| UL approval | Yes |
| cULus | Yes |
| FM approval | Yes |
| RCM (formerly C-TICK) | Yes |
| KC approval | Yes |
| Marine approval | Yes |
| Ecological footprint: environmental product declaration Global warming potential | Yes |
| Ecological footprint: global warming potential, (total) [CO2 eq] | 123 kg |
| Ecological footprint: global warming potential, (during production) [CO2 eq] | 12.1 kg |
| Ecological footprint: global warming potential, (during operation) [CO2 eq] | 111 kg |
| Ecological footprint: global warming potential, (after end of life cycle) [CO2 eq] | -0.434 kg |
Ambient conditions 11
| Free fall: Fall height, max. | 0.3 m; five times, in product package |
|---|---|
| Ambient temperature during operation: min. | -20 °C |
| Ambient temperature during operation: max. | 60 °C |
| Ambient temperature during operation: horizontal installation, min. | -20 °C |
| Ambient temperature during operation: vertical installation, min. | -20 °C |
| Ambient temperature during operation: permissible temperature change | 5°C to 55°C, 3°C / minute |
| Ambient temperature during storage/transportation: min. | -40 °C |
| Ambient temperature during storage/transportation: max. | 70 °C |
| Air pressure acc. to IEC 60068-2-13: Storage/transport, min. | 660 hPa |
| Air pressure acc. to IEC 60068-2-13: Storage/transport, max. | 1 080 hPa |
| Relative humidity: Operation at 25 ℃ without condensation, max. | 95 % |
Connection method 1
| required front connector | Yes |
|---|
Mechanics/material 1
| Enclosure material (front): Plastic | Yes |
|---|
Version Classification 4
| eClass | 16 27-24-22-04 |
|---|---|
| ETIM | 10 EC001419 |
| IDEA | 4 3566 |
| UNSPSC | 15 32-15-17-05 |
Logistics 6
| Net weight | 0.149 kg |
|---|---|
| Country of origin | DE |
| Shipping weight | 0.649 kg |
| Ships from | Türkiye |
| Dispatch | 13 Nov |
| Stock | In stock |
Source: manufacturer data · Last verified: 01 Nov 2026
Documents
Documents for 6ES7221-1BF32-0XB0
No documents are on file for this part yet.
Ask us for the datasheet
Certifications
Certifications and standards
- CE
- UL
- CE mark
- CSA approval
- UL approval
- cULus
- FM approval
- RCM (formerly C-TICK)
- KC approval
- Marine approval
Quick answers
Questions about the SM 1221, DI 8x24 V DC
What is the rated current of SM 1221, DI 8x24 V DC?
The rated current of SM 1221, DI 8x24 V DC is 0.105 A.
Which supply voltage is SM 1221, DI 8x24 V DC rated for?
The rated operational voltage of SM 1221, DI 8x24 V DC is 24 V AC.
What is the HS code of SM 1221, DI 8x24 V DC for customs?
The tariff (HS) code on file for SM 1221, DI 8x24 V DC is 85389091.
What is the EAN of SM 1221, DI 8x24 V DC?
The EAN (GTIN) of SM 1221, DI 8x24 V DC is 6940408101913.
Where does SM 1221, DI 8x24 V DC ship from, and how fast?
SM 1221, DI 8x24 V DC ships from Türkiye. Shipping calculated at checkout · import duties and taxes paid on arrival. Stock items are dispatched within 1–2 business days.
Guides
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What Is a Programmable Logic Controller and How Does It Work
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Reviews
Customer reviews
Series
Siemens SIMATIC S7-1200
- Brand
- Siemens
- Series
- SIMATIC S7-1200
