Opto 22 Analog I/O modules handle devices

Analog I/O modules handle devices that have a range of possible values. Temperature sensors and proportional valves are examples of analog devices.

Digital I/O modules handle devices that can be in only one of two states: either on or off (true or false, 0 or 1, running or stopped, etc.). Push buttons and LEDs are examples of digital devices.

SNAP Serial communication modules connect to serial devices via RS-232, RS-485/422, Profibus, or Wiegand protocol.

Brains are I/O processors that provide distributed control. Brains perform basic control functions such as on/off control, counting, and latching, as well as complex tasks such as PID control and temperature conversion.