PLC | Siemens | 6ES7321-1BH02-0AA0 6ES7 321-1BH02-0AA0 S7-300 Digital input SM 321

Product Description: Siemens 6ES7321-1BH02-0AA0

The Siemens 6ES7321-1BH02-0AA0 is a digital input module from the SIMATIC S7-300 series, designed to interface up to 16 digital input signals at 24 V DC with electronic isolation. It is used for acquiring binary signals from sensors and switches in industrial automation environments. This module offers high reliability, easy installation, and direct integration into the modular S7-300 PLC platform.

Key Features

• 16 digital inputs at 24 V DC
• Electronically isolated input channels
• Input delay filtering and diagnostics
• LED indicators for input signal status
• Standard 40 mm width module
• Seamless integration with S7-300 CPU and backplane
• Suitable for sink or source signal wiring

Technical Specifications

• Part Number: 6ES7321-1BH02-0AA0
• Number of Inputs: 16
• Input Voltage: 24 V DC (rated)
• Input Current: Approx. 7 mA per channel
• Input Type: Sink/source configurable
• Isolation: Electrically isolated from the backplane bus
• Signal Delay: Adjustable (default ~3 ms)
• Mounting Method: DIN rail (standard S7-300 rack)
• Dimensions (W × H × D): 40 mm × 125 mm × 120 mm
• Weight: Approx. 220 g
• Protection Class: IP20
• Operating Temperature: 0 °C to +60 °C
• Storage Temperature: –40 °C to +70 °C
• Certifications: CE, cULus, EAC

Application Areas

• Discrete signal acquisition in industrial automation
• Binary input detection from pushbuttons, limit switches, and sensors
• Process and factory control systems using S7-300 architecture
• Modular PLC panels requiring digital input expansion
• Automation systems with standard 24 V DC field wiring

Advantages

• Reliable and noise-immune digital signal acquisition
• Compact 16-channel design reduces hardware footprint
• LED indicators enable fast on-site diagnostics
• Compatible with all S7-300 CPUs and racks
• Robust Siemens quality for long-term industrial performance