LANC (Logic Application Control Bus System or Local Application Control Bus System), also known as Control-L is a hardware and software communication protocol invented by sony that synchronizes cameras.
The LANC terminal on sony and other manufacturers' camcorders lets accessories, such as tripods with a control handle, control the camera over a cable connected to the LANC port instead of using buttons on the camera. It is also available on many still cameras, where it is called ACC (the sony DSC-xxxx series of cameras).
The bi-directional protocol is made up of 8 (8-bit) bytes, usually clocked by the camera at 9600 bit/s. Each frame of bytes occurs in sync with the beginning of each video frame (NTSC or PAL). The physical connector is either a 5-pin mini-DIN connector and jack or a 2.5mm 3-conductor phone jack and plug (TRS connector).
In newer sony digital handycam(R) camcorders with 10-pin multi-A/V remote terminal jacks, LANC is available, but not directly accessible without making a home-made adapter cable or a pre-made cable by sony Part# J-6082-535-A. sony RM-AV2 Remote Commander is an example of a LANC controller that plugs into the sony 10-pin multi-A/V remote terminal jack.
Starting with the 2015 model year, sony has switched to a special 15 pin multiport connector that looks similar to a USB connector. However, it has 15 pins inside the connector, where a USB connection has 5. Currently, only the sony VPR-RM1 controller works with sony camcorders from 2015 and newer.
sony "Control-S" is a similar interface but is uni-directional, providing control-only, and not feedback from the controlled device.
panasonic Control-M is a similar 5-pin mini-DIN bi-directional interface and protocol with a different implementation.