About

The Simatic S7-300 Digital SM321 16DI Module is a high-quality automation module designed for industrial applications. This module comes in a standard size and rack-mount design, making it easy to integrate into existing systems. The module is colored in a sleek blue-black finish, adding a modern aesthetic to any setup. With a service period of 12 months, users can rely on its durability and performance. Suitable for exporters, manufacturers, suppliers, and traders, this module offers reliable automation capabilities for various industries. 

Siemens SIMATIC S7-300

Digital Input Module SM 321
Spare Part – Isolated 16 DI, 120/230 V AC, 1×20-pole

Supply Voltage

• Load Voltage (L1): 120/230 V AC (all load voltages must have same phase)

• Input Current (backplane bus 5 V DC): Max. 29 mA

• Power Loss (typical): 4.9 W

Digital Inputs

• Number of Inputs: 16

• Input Type: AC

• Rated Voltage: 120/230 V AC, 47–63 Hz

• Signal Levels:

  • “0”: 0–40 V

  • “1”: 79–264 V

• Input Current:

  • 16 mA (230 V, 50 Hz)

  • 6.5 mA (120 V, 60 Hz)

• Input Characteristic: IEC 61131 Type 1

• Number of Controllable Inputs:

  • Horizontal installation: Max 16 (up to 60 °C)

  • Vertical installation: Max 16 (up to 40 °C)

• Input Delay (for rated voltage):

  • 0 → 1: 25 ms

  • 1 → 0: 25 ms

• Cable Length:

  • Shielded: Max 1,000 m

  • Unshielded: Max 600 m

Encoder

• Connectable Encoders: 2-wire sensor

• Permissible Quiescent Current: Max 2 mA

Diagnostics / Status

• Alarms / Diagnostic Function: No

• LED Indicators:

  • Digital input status: Green

  • Group error SF: No

Potential Separation & Isolation

• Between Channels: No

• Between Channels (groups of 4): Yes

• Between Channels and Backplane Bus: Yes, via Optocoupler

• Isolation Tested: 4,000 V DC

Connection Method

• Required Front Connector: 20-pin

Dimensions & Weight

• Width: 40 mm

• Height: 125 mm

• Depth: 120 mm

• Weight: 240 g 

Technical Details