Modbus is the most popular protocol used in the Automation industry. Modbus Displays have built in Modbus protocol. They are available as Modbus Master or Modbus slave. Typically, these are working on Modbus RTU protocol. Baud rate and Modbus device address are programmable. Display supports 3, 6 and 16 functions and integer and floating-point numbers. Displays are available in 4 to 8 digits and from sizes 0.5 inches to 12 inches. Modbus Alphanumeric displays are also available to show a message in numeric as well as text format. Profibus is a proprietary protocol first introduced by BMBF (German department of education and research) and then used by Siemens. It is amongst the most popular protocols used in the automation industry. These displays support Profibus DP protocol. Displays are available in 4 to 8 digits and from sizes 0.5” to 12”. Profibus alphanumeric displays are also available to show a message in numeric as well as text format. These displays can thus be driven from PLCs directly which support Profibus protocol.