Simatic S7-300 Digital Input Sm 321 6ES7321-1BL00-0AA0

Application

Digital modules

Digital input/output modules possess digital inputs/outputs for the automation system. Digital sensors and actuators can be connected via these modules.

Use of the digital input modules offers the following advantages for users:

• Optimum adaptation;
  the number of inputs/outputs can be adapted to the respective task using optional combination of modules. Superfluous investments no longer exist
• Flexible process connection;
  the automation system can be connected to the process using many different digital actuators and sensors

Analog modules

Analog input/output modules contain analog inputs/outputs for the automation system. Via these modules, analog sensors and actuators can be connected to the automation system. 
Use of the analog input/output modules offers users the following advantages:

• Optimal adaptation:
  The number of inputs/outputs can be adapted to a particular task through the appropriate module combination. There is no unnecessary investment cost.
• Powerful analog technology:
  Different input/output ranges and high resolution allow connection of many different analog sensors and actuators.

Ex digital/analog modules

The Ex modules are available as associated equipment for the automation of chemical plants. They can be used for instrumentation and control applications.

Fields of application:

• Chemical/petrochemical industry
• Gas industry
• Offshore technology
• Transport (e.g., oil tankers, tank trucks)
• Automotive industry (e.g., in paint shops)
• Power supply, power distribution etc.
• Power stations
• Specialized mechanical engineering (e.g., printing machines, industrial cleaning machines).

The modules may not be used in areas subject to explosion hazard, unless they are additionally protected by another type of protection (e.g., pressurized enclosure).

The modules are approved for the connection of intrinsically-safe sensors and actuators located in Zone 1 or Zone 2 of areas subject to explosion hazard.

The modules can be used:

• In the SIMATIC S7-300 programmable controller
• In the ET 200M remote I/O device, can be used as distributed I/O for all SIMATIC S5/S7/505 programmable controllers and as a standard slave on all PROFIBUS DP networks