Product Overview
Technical Summary
| Parameter | Value |
|---|---|
| Module type | SM 1221, DI 16x 24 V DC |
| Digital inputs | 16 |
| Rated input voltage | 24 V DC |
| Signal 0 | 5 V DC or 0.5 mA |
| Signal 1 | 15 V DC at 2.5 mA |
| Input delay | 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 |
| Backplane bus current | 90 mA at 5 V DC, max. |
| Power loss | 3.2 W, typ. |
| Isolation | 707 V DC (type test) |
| Protection | IP20 |
Applications
- Digital signal acquisition: Acquires 24 V DC sink/source digital input signals through 16 DI channels.
Key Features
- Digital input channels: 16 digital inputs for 24 V DC sink/source signals, arranged in groups of 4.
- Input signal thresholds: Signal 0: 5 V DC or 0.5 mA; signal 1: 15 V DC at 2.5 mA.
- Configurable input delay: Standard inputs support selectable delays of 0.2 ms, 0.4 ms, 0.8 ms, 1.6 ms, 3.2 ms, 6.4 ms, and 12.8 ms in groups of four.
- Diagnostics indication: The module has input-status and maintenance diagnostic LEDs; diagnostic alarms and supply-voltage monitoring are not available.
- Electrical isolation: Digital inputs have potential separation between channels in groups of 4 and between the channels and backplane bus: 707 V DC (type test).
- Protection and cable length: IP20 protection; maximum cable length is 500 m shielded or 300 m unshielded.
Frequently Asked Questions
1. How many digital inputs does the Siemens 6ES7221-1BH50-0XB0 have?
It has 16 digital inputs, arranged in groups of 4.
2. What input signals does the SM 1221 support?
It supports 24 V DC sink/source inputs. Signal 0 is 5 V DC or 0.5 mA, and signal 1 is 15 V DC at 2.5 mA.
3. Can the input delay be configured?
Yes. Standard inputs support 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.
4. What diagnostic indications are available?
Diagnostic LEDs indicate input status and maintenance. Diagnostic alarms and supply-voltage monitoring are not available.
