The Siemens 6AG1221-1BF32-2XB0 is an 8-channel digital input module for the S7-1200 system, rated for 24 V DC sink inputs with a permissive range of 20.4 V to 28.8 V DC. The module draws 105 mA max from the 5 V DC backplane bus and nominally 1.5 W from the load supply. Each input group of two channels shares common isolation, so you land the return per pair. Signal thresholds are defined per the Siemens spec: a logic '1' is guaranteed at ≥15 V DC with a source current of 2.5 mA minimum, 4 mA typical; logic '0' is ≤5 V DC with a permissible quiescent current of 1 mA max. The part is parameterizable, provides diagnostic alarm and status indication per channel, and includes supply voltage monitoring. For longer cable runs, unshielded cable is good to 300 m; shielded stretches to 500 m. IP20 protection keeps it inside the control cabinet.
Siemens 6AG1221-1BF32-2XB0 8 DI 24V, -40..70°C
MPN6AG1221-1BF32-2XB0
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Siemens 6AG1221-1BF32-2XB0, S7-1200 digital input module, 8 channels, 24 V DC sink, 45 mm wide, ambient -40…70 °C, 1.5 W typ., diagnostic alarm, current production.
$144.78 – $398.14Ref. price · indicative, final on quote
Sourced new & surplus through independent channelsAuthenticity-screened · ESD-safe packingListing updated Aug 2026
Specifications
| Parameter | Value |
|---|---|
| Number of digital inputs | 8 |
| Max. inputs, up to 40 °C | 8 |
| Parameter | Value |
|---|---|
| Rated value (DC) | 24 V |
| Input voltage at signal "1" | 15 V DC at 2.5 mA |
| Input voltage at signal "0" | 5 V DC at 1 mA |
| Permissible range, lower limit (DC) | 20.4 V |
| Permissible range, upper limit (DC) | 28.8 V |
| Input current at signal "1" (typ.) | 4 mA |
| Input current at signal "0", max. (permissible quiescent current) | 1 mA |
| Power loss (typ.) | 1.5 W |
| Current consumption from backplane bus (5 V DC), max. | 105 mA |
| Cable length, unshielded, max. | 300 m |
| Cable length, shielded, max. | 500 m |
| Parameter | Value |
|---|---|
| Input delay, parameterizable values | Yes |
| Parameter | Value |
|---|---|
| Diagnostics function | Yes |
| Diagnostic alarm | Yes |
| Channels per isolated group | 2 |
| Parameter | Value |
|---|---|
| Depth | 75 mm |
| Height | 100 mm |
| Width | 45 mm |
Product details
Frequently asked questions
What are the operating temperature limits for this module?
The module is rated for ambient air temperature from -40 °C to +70 °C, with a cold-restart minimum of -25 °C.
MPN
6AG1221-1BF32-2XB0