Product Description
Key Features
- Product identity: SIMATIC S7-1200 digital input SM 1221; product type designation: SM 1221, DI 8×24 V DC.
- Digital inputs: Has 8 digital inputs in groups of 2, with an IEC 61131 type 1 input characteristic curve.
- Input voltage: Rated input voltage: 24 V DC; signal "0": 5 V DC at 1 mA; signal "1": 15 V DC at 2.5 mA.
- Supply voltage: Rated supply voltage: 24 V; permissible range: 20.4 V to 28.8 V.
- Installation and protection: IP degree of protection: IP20. Maximum digital input count is 8 for all mounting positions up to 40 °C, horizontal installation up to 40 °C and 50 °C, and vertical installation up to 40 °C.
Applications
- Digital signal input: Receives digital input signals through 8 digital inputs.
Technical Summary
| Product type designation | SM 1221, DI 8×24 V DC |
|---|---|
| Digital inputs | 8 |
| Input grouping | In groups of 2 |
| Rated input voltage | 24 V DC |
| Signal "0" input voltage | 5 V DC at 1 mA |
| Signal "1" input voltage | 15 V DC at 2.5 mA |
| Rated supply voltage | 24 V |
| Permissible supply voltage range | 20.4 V to 28.8 V |
| Backplane bus input current, max. | 105 mA at 5 V DC |
| Protection | IP20 |
| Lifecycle | Active Product |
Frequently Asked Questions
What is the exact order number and product type?
The exact order number is 6ES7221-1BF32-0XB0. The product type designation is SM 1221, DI 8×24 V DC.
How many digital inputs does this module have?
It has 8 digital inputs in groups of 2.
What input voltage does it use?
The rated input voltage is 24 V DC. Signal "0" is 5 V DC at 1 mA, and signal "1" is 15 V DC at 2.5 mA.
What protection rating is supplied?
The degree of protection is IP20.
