Siemens SIMATIC S7-300 16-Channel Digital Input Module

Description

This is the Siemens SM 321 digital input module, part number 6ES7 321-1BH02-0AA0, for the SIMATIC S7-300 PLC system. It provides 16 optically isolated inputs for 24V DC signals, ensuring reliable and safe signal acquisition from various field devices like sensors and switches. It is a fundamental component for expanding the capabilities of your automation projects.

Specifications

• Manufacturer: Siemens
• Product Line: SIMATIC S7-300
• Model: SM 321
• Part Number: 6ES7 321-1BH02-0AA0
• Number of Digital Inputs: 16
• Input Voltage: 24V DC
• Isolation: Optically Isolated
• Connector: 1x 20-pole

Label Info

• E-Stand: 3
• Serial Number: S C-S8F60196

Application

Designed for use in the SIMATIC S7-300 and ET 200M automation systems. Ideal for applications requiring the acquisition of digital control signals in manufacturing, process control, and machine building.

Country of Origin

Made in Germany.

CO2 Impact

By purchasing this pre-owned module, you help avoid the emission of approximately 8 kg of CO2 associated with the production of a new one. This saving is comparable to the emissions of a 40 km car journey.

Availability

This is an obsolete item but is available from our stock. Order now from PLC2Day for expert support and fast delivery.

FAQ

Yes, the S7-300 I/O modules, including the 6ES7 321-1BH02-0AA0, can be used as distributed I/O on an S7-400 system using an ET 200M interface module (e.g., IM 153).

The standard input delay for the 6ES7 321-1BH02-0AA0 is typically 1.2 to 4.8 ms, which is configurable in the hardware settings of your programming software (e.g., SIMATIC Manager or TIA Portal).

No, this is a standard digital input module. For safety-related applications, you must use Siemens F-series (Failsafe) modules, which are specifically designed and certified for that purpose.

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Last Update: Friday, March 13, 2026