Digital input modules allow the connection of the controller to digital signals of the process.

This provides users with the following advantages:

• Optimum adaptation:
  With signal modules which can be mixed as desired, users can adapt their controllers exactly to the relevant task. This avoids superfluous investments. Modules with 8, 16, and 32 input/output channels are available.
• Flexibility:
  If the task is expanded subsequently, the controller can be upgraded. Updating of the user program is extremely simple.