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SIEMENS 6ES7321-1BL00-0AA0

Siemens 6ES7321-1BL00-0AA0,  SIMATIC S7-300 SM 321 Digital Input Module, (32) 24V DC Digital Inputs, 4 Groups of 8, Sinking, 40-Pin, Optically Isolated.





Article Number 6ES73211BL000AA0
Product Description SIMATIC S7-300, Digital input SM 321, Isolated 32 DI, 24 V DC, 1x 40-pole
Product family SM 321 digital input modules
Product Lifecycle (PLM) PM300:Active Product


Delivery information

Export Control Regulations AL : N / ECCN : EAR99H
Standard lead time ex-works 1 Day/Days
Net Weight (lb) 0.659 lb
Product Dimensions (W x L x H) Not available
Packaging Dimension 5.157 x 5.748 x 2.008
Package size unit of measure in
Quantity Unit 1 Piece
Packaging Quantity 1

Additional Product Information

EAN 4025515060772
UPC 662643175493
Commodity Code 85389091
LKZ_FDB/ CatalogID ST73
Product Group 4031
Country of origin Germany
Compliance with the substance restrictions according to RoHS directive 03/31/2008
Returnable Yes
WEEE (2012/19/EU) Take-Back Obligation Yes



Digital input modules can be used to connect the PLC to digital process signals. They are suitable for connecting standard switches and two-wire proximity switches (BERO).


Digital input modules feature the following mechanical characteristics:

  • Compact design:
    The rugged plastic housing contains:

    • Green LEDs for indicating the signal status at the inputs.
    • Socket for the front connector, protected, behind the front door.
    • Labeling field on the front door.
    • Connector pin assignment for the wiring on the inside of the front door.
  • Easy installation:
    There are no slot rules, the addresses of the inputs are determined by the slot.
    When used in ET 200M in combination with active bus modules, hot swapping is possible without any reaction.
  • User-friendly wiring.

The modules are available with 8, 16, 32, or 64 channels.


Digital input modules convert the level of the external digital signals from the process to the internal signal level (logical “0” or “1”) of the controller.

Various input voltages support the connection of different process signals:

  • 24 V DC
  • 48 to 125 V DC
  • 120/230 V AC

Apart from cost-effective, easy-to-handle modules, modules with special functions are also available:

  • For use in isochronous mode
  • Process and diagnostic alarms
  • Use for current sourcing or current sinking

Special modules are also available for process engineering which, for example, support the NAMUR standard.