RS-232 is a communications standard for serial communications between devices. In CCTV, this can be communication between a controller and a surveillance camera. The RS-232 standard allows for the connection of two devices through a serial link, and is the protocol used for serial connections in computers. RS-485 allows for serial connections between more than 2 devices on a networked system and is defined below.
RS485, also referred to as EIA-485 is a communications standard for serial communication between devices. When talking about surveillance systems, RS-485 is typically used as the protocol to allow computers and remote controllers to control the activity of cameras such as pan, tilt, rotate, and zoom operations. RS485 is an updated version of the original serial protocol, RS-232.