The Sony 9-Pin Protocol or P1 protocol is a two-way

communications protocol A communication protocol is a system of rules that allows two or more entities of a communications system to transmit information via any kind of variation of a physical quantity. The protocol defines the rules, syntax, semantics and synch ...

to control advanced video recorders. Sony introduced this protocol to control reel-to-reel type C

video tape recorder A video tape recorder (VTR) is a tape recorder designed to record and playback video and audio material from magnetic tape. The early VTRs were open-reel devices that record on individual reels of 2-inch-wide (5.08 cm) tape. They were u ...

s (VTR) as well as

videocassette recorder A videocassette recorder (VCR) or video recorder is an electromechanical device that records analog audio and analog video from broadcast television or other source on a removable, magnetic tape videocassette, and can play back the reco ...

s (VCR). It uses an DE-9 D-Sub connector with 9 pins (hence the name), where bi-directional communication takes place over a four wire cable according to the RS-422 standard. While nowadays all

post-production Post-production is part of the process of filmmaking, video production, audio production, and photography. Post-production includes all stages of production occurring after principal photography or recording individual program segments. Th ...

editing is done with a non-linear editing system, in those days editing was done

linearly Linearity is the property of a mathematical relationship (''function'') that can be graphically represented as a straight line. Linearity is closely related to '' proportionality''. Examples in physics include rectilinear motion, the linear re ...

, using online editing. Editing machines relied heavily on the 9-Pin Protocol to remotely control automatic players and recorders. Many modern

hard disk recorder A hard disk recorder (HDR) is a system that uses a high-capacity hard disk to record digital audio or digital video. Hard disk recording systems represent an alternative to reel-to-reel audio tape recording and video tape recorders, and provide ...

s and

solid-state drive A solid-state drive (SSD) is a solid-state storage device that uses integrated circuit assemblies to store data persistently, typically using flash memory, and functioning as secondary storage in the hierarchy of computer storage. It is a ...

recorders can still emulate a 1982 Sony BVW-75

Betacam Betacam is a family of half-inch professional videocassette products developed by Sony in 1982. In colloquial use, "Betacam" singly is often used to refer to a Betacam camcorder, a Betacam tape, a Betacam video recorder or the format itself. Al ...

tape recorder. Sony's standard also specifies a pinout: {, class="wikitable" style="margin:auto;" ! Pin !! on master !! on slave , - , 1 , , Frame ground , , Frame ground , - , 2 , , Receive A , , Transmit A , - , 3 , , Transmit B , , Receive B , - , 4 , , Transmit common , , Receive common , - , 5 , , Spare or ground , , Spare or ground , - , 6 , , Receive common , , Transmit common , - , 7 , , Receive B , , Transmit B , - , 8 , , Transmit A , , Receive A , - , 9 , , Frame ground , , Frame ground , - This 9-pin RS-422 pinout has become a

de facto ''De facto'' ( ; , "in fact") describes practices that exist in reality, whether or not they are officially recognized by laws or other formal norms. It is commonly used to refer to what happens in practice, in contrast with '' de jure'' ("by l ...

standard, used by most brands in the broadcast industry. In the new millennium, RS-422 is slowly phased out in favor of

Ethernet Ethernet () is a family of wired computer networking technologies commonly used in local area networks (LAN), metropolitan area networks (MAN) and wide area networks (WAN). It was commercially introduced in 1980 and first standardized in 1 ...

for control functions. However its simple way to perform

troubleshooting Troubleshooting is a form of problem solving, often applied to repair failed products or processes on a machine or a system. It is a logical, systematic search for the source of a problem in order to solve it, and make the product or process ope ...

means it will stay around for a long time. In

broadcast automation Broadcast automation incorporates the use of broadcast programming technology to automate broadcasting operations. Used either at a broadcast network, radio station or a television station, it can run a facility in the absence of a human op ...

the

Video Disk Control Protocol Video Disk Control Protocol (VDCP) is a proprietary communications protocol primarily used in broadcast automation to control hard disk video servers for broadcast television. VDCP was originally developed by Louth Automation and is commonly calle ...

(VDCP) use the 9-Pin Protocol to

playout In broadcasting, channel playout is the generation of the source signal of a radio or television channel produced by a broadcaster, coupled with the transmission of this signal for primary distribution or direct-to-audience distribution via any ...

broadcast programming Broadcast programming is the practice of organizing or ordering (scheduling) of broadcast media shows, typically radio and television, in a daily, weekly, monthly, quarterly or season-long schedule. Modern broadcasters use broadcast automation ...

schedules.

External links

* Sony 9-Pin Remote Protocol (Archived

References

*Protocol of Remote-1 (9-pin) Connector, 2nd Edition, Sony, document number 9-977-544-13 Communications protocols Serial buses Television terminology