Product details
The Siemens SIMATIC S7-300 SM 321 (6ES7321-1BH02-0AA0) is the genuine 16-channel 24 V DC digital input module – the single most common input module across the S7-300 installed base. Fits both S7-300 CPU racks and ET 200M distributed I/O stations, making it one of the most widely installed modules of the platform in Australian plants.
- 16 digital inputs, 24 V DC
- 1 x 20-pole front connector required (order separately)
- The default DI module of the S7-300 era – enormous installed base
- Fits S7-300 CPU racks and ET 200M stations
- Discontinued by Siemens – sourced to order
Technical specifications
| Order number | 6ES7321-1BH02-0AA0 |
| Product range | SIMATIC S7-300 |
| Type | SM 321 digital input module |
| Inputs | 16 x DI |
| Rated input voltage | 24 V DC |
| Front connector | 20-pole (not included) |
| Width | 40 mm |
| Lifecycle status | Discontinued (Siemens phase-out October 2025) |
End-of-life availability
Siemens ended new production of the S7-300 / ET 200M range in October 2025, with official spares support winding down towards 2033. New units are no longer available through authorised channels. We source genuine S7-300 stock through our global parallel-import network specifically for Australian plants that need to keep existing installations running.
Request a quote online or call our team on 0403 082 383 to confirm stock, condition and lead time for the 6ES7321-1BH02-0AA0.
InstroDirect is an independent reseller and is not an authorised Siemens distributor. All products are 100% genuine, sourced through legitimate parallel-import channels.
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