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.

SM 321 digital input modules Function

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.

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SM 321 digital input modules Ordering data

Product No. / Product Description		Listprice / Your price
		6ES7321-1BH02-0AA0 SIMATIC S7-300, Digital input SM 321, isolated, 16 DI, 24 V DC, 1x 20-pole
		6ES7321-1BH10-0AA0 SIMATIC S7-300, Digital input SM 321, isolated, 16 DI, 24 V DC, 1x 20-pole, 0.05 ms input delay
		6ES7321-1BH50-0AA0 SIMATIC S7-300, Digital input SM 321, Isolated 16 DI, 24 V DC, Source input, 1x 20-pole
		6ES7321-1BL00-0AA0 SIMATIC S7-300, Digital input SM 321, Isolated 32 DI, 24 V DC, 1x 40-pole
		6ES7321-1BP00-0AA0 SIMATIC S7-300 digital input SM 321, Isolated in groups of 16, 64 DI, 24 V DC, 3ms, Sink/source input Terminal blocks 6ES7392-1.N00-0AA0 and cable 6ES7392-4…0-0AA0 required
		6ES7321-1CH00-0AA0 SIMATIC S7-300, Digital input SM 321, isolated, 16 DI, 24-48 V AC/DC with single rooting, 1x 40-pole
		6ES7321-1CH20-0AA0 SIMATIC S7-300, Digital input SM 321, isolated, 16 DI, 48-125 V DC, 1x 20-pole
		6ES7321-1EL00-0AA0 SIMATIC S7-300, Digital input SM 321, isolated, 32 DI, 120 V AC, 1x 40-pole
		6ES7321-1FF01-0AA0 SIMATIC S7-300, Digital input SM 321, isolated, 8 DI, 120 V/230 V AC, 1x 20-pole
		6ES7321-1FF10-0AA0 SIMATIC S7-300, Digital input SM 321, isolated, 8 DI, 120 V/230 V AC, 1x 40-pole, with single rooting/channel

		6ES7321-1FH00-0AA0 SIMATIC S7-300, Digital input SM 321, Isolated 16 DI, 120/230 V AC, 1x 20-pole
		6ES7321-7BH01-0AB0 SIMATIC S7-300, Digital input SM 321, isolated, 16 DI; 24 V DC, 1x 20-pole, process interrupt, diagnostics, suitable for isochronous mode