Had a question today…”What does LANC stand for?” If you are involved in the video field, then you probably already realize that you can use a LANC jack on a camcorder to attach external camera controls and such (like a zoom rocker for your tripod). I did a little digging, and here’s a LOT more info on LANC, courtesy of “Rodney”. I’ve chopped up and posted here what seems relevant from the original text.

“LANC stands for Local Application Control Bus. Don’t ask me why they chose the letters LANC to stand for what it does. :-) LANC, also known as Control-L, is an editing protocol which has been included on some camcorders and VCRs for at least ten years…

…In addition, LANC camcorders can be controlled remotely by a LANC remote just like the IR remote, in some cases allowing zoom, focus, and quasi-stop frame or time-lapse sequences. (The TRV900 has a built-in intervalometer for time-lapse, but most other cameras lack this feature, and the few commercial LANC controllers with time-lapse are apparently discontinued.) Some underwater housings allow control of
the camera via a LANC wire.

Like all other current Sony camcorders, my Sony is equipped with a 3/32″ stereo jack for LANC control. Physically the format is 9600 baud serial, one-line bidirectional (open collector); eight bytes per video frame. Control L is a two-way serial open collector 9600 baud protocol. Cameras (control-L) use a three pin sub-mini jack that has ground on the sleeve, power (up to 100ma unregulated 5-9v) at the tip and LANC signal on the ring…

…The LANC bus is an open collector so it is normally pulled high to about 5v and is pulled low to send commands or status information. You can hook the LANC signal directly to the input of a 1488 RS232 line driver and feed that into your PC serial port and capture the 9600 baud data stream. It will have to be inverted before you use it (00 will read as FF).

The data stream is 8 bytes, then a gap (1.7ms? until the end of the current frame) then 8 bytes for the next frame, another gap and so on. If you can write your serial driver to sync to that gap you can read it easily.

The camcorder puts out an 8 byte data packet with each video frame. The first two bytes are for controllers to command the camera and are usually 00 00. The next two are for tuners and are also usually 00 00. The last four bytes are for the VCR status and carry the counter and several other status bits.”

A little techie, but good to know anyway.