The Field Control distributed I/O and control system from the GE Fanuc company is made up of modular I/O products that can fit many different control system architectures. The devices included in the Field Control system series are I/O modules, I/O terminal blocks, and Bus interface units. The I/O modules are designed to be rugged and they can provide an analog I/O interface. The I/O terminal blocks are the universal field-wiring terminals for 2 of the I/O modules at a time, which means that different kinds of I/O modules can be mounted on the same I/O terminal block. The I/O terminal blocks in turn are mounted on DIN rails, and the DIN rails need to be mounted on panels because they are part of the grounding system. The Bus interface unit can support up to 4 I/O terminal blocks or up to 8 I/O modules in a Field Control “station.”

The DIN Rail that the Field Control I/O terminal blocks are mounted on must be a 35 millimeters x 7.5 millimeters DIN Rail and the rail must have a conductive or unpainted finish to allow for proper grounding. Note that the I/O terminal blocks can protect the I/O modules installed in them from the negative effects of ESD or electrostatic discharge, but that uninstalled I/O modules are sensitive to ESD and static control precautions must be taken when handling and installing them. To ensure that the I/O modules are as secure as possible, the users can utilize the optional module key clips and slots to hold them in place or in a specific position.