Control S (also known as S-Link or SIRCS) is Sony's proprietary control bus protocol used for system integration between compatible Sony audio and video equipment.
Overview
Control S allows one device to control another via simple pulse-width modulated commands sent over a single wire. It was introduced in the 1980s and remained common on Sony equipment through the 2000s.
The protocol is based on Sony's SIRCS (Sony Infrared Remote Control System) — the same encoding used by Sony infrared remotes, but transmitted electrically rather than optically.
Specifications
| Parameter | Value |
|---|---|
| Signal type | Pulse-width modulated digital |
| Voltage | 5Vp-p typical |
| Connector | 3.5mm mono mini-jack (TS) |
| Direction | Unidirectional (per jack) |
Common Uses
- Linking monitors to tuners (e.g., Profeel Pro + VT-X5R)
- Synchronizing VCRs with TVs for timer recording
- Controlling multiple components from a single remote
- System power on/off synchronization
Equipment
Control S was featured on many Sony products including:
- Profeel and Profeel Pro monitors (Sony KX-21HV1, Sony KX-27HV1)
- Trinitron televisions
- Betamax and VHS VCRs
- LaserDisc players
- Audio receivers and amplifiers
