SCART (from Syndicat des Constructeurs dAppareils Radiorécepteurs et Téléviseurs) is a French-originated standard and associated 21-pin connector for connecting audio-visual equipment together. It is also known as Péritel (especially in France) and Euroconnector. SCART makes it easy to connect AV equipment (including TVs, VCRs, DVD players and games consoles). In essence, it gathers together various common analog signal-types into a single connector. Nowdays is obsolete and superseded by HDMI. The signals carried by SCART include both composite and RGB video, and stereo audio input/output, as well as support functions. May be converted to VGA, S-video.The voltage levels are rather high, around 1V, so the signals have good noise immunity.
SCART details
SCART is bi-directional regarding standard composite video and analog audio. A television set will typically send the antenna audio and video signals to the SCART sockets all the time and watch for returned signals, to display and reproduce them instead. This allows to have transparent set-top boxes, without any tuner, which just hook and pre-process the television signals. A VCR may have 2 SCART sockets, one connecting to the television set, and another one for the set-top box. When idle or powered off, the VCR will forward the signals from the television set to the set-top decoder and send the processed result back to the television set. When a scrambled show is recorded, the VCR will drive the set-top box from its own tuner and send the unscrambled signals to the television set for viewing or simple recording control purposes. In addition, SCART allows a connected device to power on and power off a television set, more precisely: to bring it in and out of standby mode, in the same way as a remote control would do.
SCART pinouts
Different pin-configurations exist. Which confirations are available depends on the video device used. Sometimes one can choose the configuration (like composite or S-video) by changing a software setting.
Two status signals define (partly) which video signals are active. A video device can use these status signals to automatically switch between internal or external audio/video signals.
| Pin | Name | Description | Signal Level | Impedance |
|---|---|---|---|---|
| 1 | AOR | Audio Out Right | 0.5 V rms | <1k ohm |
| 2 | AIR | Audio In Right | 0.5 V rms | >10k ohm |
| 3 | AOL | Audio Out Left + Mono | 0.5 V rms | <1k ohm |
| 4 | AGND | Audio Ground | ||
| 5 | B GND | RGB Blue Ground | ||
| 6 | AIL | Audio In Left + Mono | 0.5 V rms | >10k ohm |
| 7 | B | RGB Blue In | 0.7 V | 75 ohm |
| 8 | SWTCH | Audio/RGB switch / 16:9, slow switch (10-12v), to force tv to switch on a mode (depends of the tv(old), sometimes set tv to AUX) | ||
| 9 | G GND | RGB Green Ground | ||
| 10 | CLKOUT | Data 2: Clockpulse Out, used in the 80s by old videotapes | ||
| 11 | G | RGB Green In | 0.7 V | 75 ohm |
| 12 | DATA | Data 1: Data Out (Unavailable ??) | ||
| 13 | R GND | RGB Red Ground | ||
| 14 | DATAGND | Data Ground, remote control, wired and used by old videotape recorders | ||
| 15 | R | RGB Red In / Chrominance | 0.7 V (Chrom.: 0.3 V burst) | 75 ohm |
| 16 | BLNK | Blanking Signal, fast switch (1-3v), to force tv to switch on a mode (depends of the tv(recent), sometimes set tv to AUX) | 1-3 V=RGB, 0-0.4 V=Composite | 75 ohm |
| 17 | VGND | Composite Video Ground or S-video luminance Ground | ||
| 18 | BLNKGND | Blanking Signal Ground - ground for slow or fast switch (ground for pin 8 or 16) | ||
| 19 | VOUT | Composite Video Out | 1 V | 75 ohm |
| 20 | VIN | Composite Video In / Luminance / RGB Sync | 1 V | 75 ohm |
| 21 | SHIELD | Ground/Shield (Chassis) |
Two pins provide switching signals.
Pin 8, the function switching pin, carries a low frequency (less than 50Hz) signal from the source that indicates the type of video present.
0V-2V means no signal, or internal bypass
4.5V-7V (nominal 6V) means a widescreen (16:9) signal
9.5V-12V (nominal 12V) means a normal (4:3) signal
Pin 16, the fast switching pin, carries a signal from the source that indicates that the signal is either RGB or composite.
0V-0.4V means composite.
1V-3V (nominal 1V) means RGB only.
The original specification defined pin 16 as fast blanking, a high frequency (up to 3MHz) signal that blanked the composite video. The RGB inputs were always active and the fast blanking signal punches holes in the composite video. The SCART connector uses this to overlay subtitles from an external Teletext decoder. 0V-0.4V means composite with a transparent RGB overlay. 1V-3V (nominal 1V) RGB only.
There is no switching signal to indicate S-Video. Some TVs can autodetect the presence of the S-Video signal but more commonly the S-Video input needs to be manually selected.
SCART availability
Many older TV sets have 2 SCART sockets. One is usually uses previous pinout table and the other uses following pinout table. The first can switch from a composite input to RGB input. The second can switch from a composite input to an S-Video input, pin 20 being either composite in or luminance in. Usually the second socket outputs a selectable composite signal on pin 19
| Pin | Signal | Level | Impedance |
| 1 | Audio Out Right | 0.5 V rms | <1k ohm |
| 2 | Audio In Right | 0.5 V rms | >10k ohm |
| 3 | Audio Out Left + Mono | 0.5 V rms | <1k ohm |
| 4 | Ground Audio | ||
| 5 | RGB Ground Blue | ||
| 6 | Audio In Left + Mono | 0.5 V rms | >10k ohm |
| 7 | - | - | - |
| 8 | Fuction Select | High (9.5-12V) AVmode Low (0-2V) TVmode |
>10kohm |
| 9 | RGB Ground Green | ||
| 10 | Comms Data 2 | ||
| 11 | - | - | - |
| 12 | Comms Data 1 | ||
| 13 | Ground (chrominance) | ||
| 14 | Ground Data | ||
| 15 | Chrominance input | 0.3V | 75 ohm |
| 16 | - | - | - |
| 17 | Ground (luminance) | ||
| 18 | - | - | - |
| 19 | Video output (composite) | 1V including sync | 75 ohm |
| 20 | Luminance input | 1V including sync | 75 ohm |
| 21 | Ground/Shield (Chassis) |
SCART Signal Levels
| Signal | AC level | DC level | Impedance |
|---|---|---|---|
| Red, green, blue | Peak to blanking: 0...0.7 V ?3 dB | 0...2 V | 75 Ohm |
| Sync | Peak to peak: 0...0.3 V -3 dB...+10 dB | 0...2 V | 75 Ohm |
| Composite video | White to sync: 0...1.0 V ?3 dB | 0...2 V | 75 Ohm |
| Chrominance | 0...0.3 V -3 dB...+10 dB | 0...2 V | 75 Ohm |
| Luminance | 0...1.0 V 3 dB | 0...2 V | 75 Ohm |
| MAC | Black to white: 0...1.0 V 3 dB | 0...2 V | 75 Ohm |
| Audio in | 0.2...2.0 V (nominal: 0.5 V) | >=10 kOhm | |
| Audio out | Nominal: 0.5 V (maximum: 2.0 V) | <=1 kOhm | |
| Video status | Low data rate communication: 0.0...2.0 V (e.g. remote control; Easylink) |
Internal: 0.0...2.0 V External (16:9): 4.5...7.0 V External (4:3): 9.5...12.0 V |
In: ZR>=10 kOhm ZC<=2 nF Out: ZR<=1 kOhm |
| RGB status | Internal: 0.0...0.4 V External: 1.0...3.0 V |
75 Ohm |
A formal interface description is given in the CENELEC EN 50 049-1:1989 standard or in the IEC 933-1 standard.
Some tables:
SCART to S-Video cable
| Output connector | Input connector | ||
|---|---|---|---|
| 1 | Audio right out | 2 | Audio right in |
| 3 | Audio left (or mono) out | 6 | Audio left (or mono) in |
| 4 | Audio return | 4 | Audio return |
| 15 | Chrominance out | 15 | Chrominance in |
| 13 | Chrominance return | 13 | Chrominance return |
| 8 | Video status out | 8 | Video status in |
| 19 | Luminance out | 20 | Luminance in |
| 17 | Luminance return |
17 |
Luminance return |
| 21 | Shield | 21 | Shield |
SCART to Composite Video cable
| Output connector | Input connector | ||
|---|---|---|---|
| 1 | Audio right out | 2 | Audio right in |
| 3 | Audio left (or mono) out | 6 | Audio left (or mono) in |
| 4 | Audio return | 4 | Audio return |
| 8 | Video status out | 8 | Video status in |
| 19 | Composite video out | 20 | Composite video in |
|
17 |
Composite video return | 17 | Composite video return |
| 21 | Shield | 21 | Shield |
Composite Decoder Connection
| Receiver connector | Decoder connector | ||
|---|---|---|---|
| 1 | Audio right out | 2 | Audio right in |
| 2 | Audio right in | 1 | Audio right out |
| 3 | Audio left out | 6 | Audio left in |
| 6 | Audio left in | 3 | Audio left out |
| 4 | Audio return | 4 | Audio return |
| 8 | Video status in | 8 | Video status out |
| 19 | Baseband out (scrambled) | 20 | Baseband in |
| 17 | Baseband out return | 18 | Baseband in return |
| 20 | Composite video in (unscrambled) | 19 | Composite video out |
|
17 |
Composite video in return | 17 | Composite video out return |
| 21 | Shield | 21 | Shield |
EasyLink Connection (additional)
| Television connector | Video recorder connector | ||
|---|---|---|---|
| 10 | I/O Control Bus | 10 | I/O Control Bus |
EasyLink enables bi-directional communication between a television set and a video recorder. This way a video recorder can, for example, copy the channel settings of the television set. Who knows the details?
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