The Allen-Bradley Programmable Logic Controllers with the most flexibility and support for the largest number of inputs and outputs in the Micro800 series are the Allen-Bradley Micro850 PLCs. These flexible configured PLCs can have up to 5 base plug-in slots that can use an additional 4 expansion I/O slots to provide control over 132 I/O points. Digital inputs can operate with 12 and 24 Volts DC as well as 120 Volts AC. The digital outputs supported by these controllers can be 24 Volts DC source or sink outputs and relays. The Micro850 PLCs are programmed by using the Function Block, Ladder Diagram, or Structured Text Language via the universal and free-downloadable Connected Components Workbench software developed by Allen-Bradley which supports both HMI devices and AC drives.

The content uploaded to the Micro850 PLCs can be saved for backup on an SD card and it can be protected from unauthorized access by a password. The devices have an EtherNet/IP Class 3 Modbus TCP (10 to 100Mbps) Ethernet port, a USB 2.0 programming port, and a power supply port integrated. The Micro850 PLCs are very practical for the assembly and connection of input/output devices because they support removable terminal blocks. The Allen-Bradley Micro850 series has the capacity to control a maximum of 3 axes by using a step or servo motor with the TouchProbe instruction technology that remembers the axis position on the machine with higher accuracy than interrupts do. The Micro850 series controllers are available as 24-point or 48-point options, they have 10 K steps of programming instructions available, and they support PID loops for regulating the variable measuring values of virtually all industrial processes.