Depending what type of control network you are connecting to, will generally determine the type of Opto 22 brain that is required in the control and data acquisition system. Control networks, in the majority of cases, utilize a computer, which will require a connection to the brain using an interface card such as serial (RS232/RS485/RS422) or Ethernet. Opto 22 brain boards have one or both of these connections incorporated so as to facilitate connection between the field instrumentation and the computer. Serial Opto 22 brains include the B1, B2, E1, E2, SNAP-PAC-R1, SNAP-PAC-R2, SNAP-PAC-SB1, SNAP-PAC-SB2 and EPIC to name just a few.

The physical connection is only half the story though. Once this is made, the Opto 22 brain has to also speak the same language as the computer software. So, Opto 22 brains are designed to speak different languages, known as protocols. Such protocols include proprietary ones such as OptoMMP, MISTIC, Optomux, PAMUX, Modbus, EtherNET IP, DeviceNET and many more.