The ABB FW/S8.2.1 Radio Time Switch is an MDRC KNX master clock with 8 programmable time channels. It broadcasts time/date on the bus and can synchronize from an optional FAD/A1.1 DCF/GPS antenna.

Auxiliary supply 110–240 V AC. Time programs are edited in ETS for scheduled lighting, HVAC enable, or scene triggers—without relay power outputs on the device itself.

Key Features

• 8 logical channels: Independent time programs on KNX.
• Bus time/date: Master clock for the installation.
• Optional radio sync: DCF77 / GPS via FAD/A1.1 accessory.
• Auxiliary supply: 110–240 V AC (not bus-only).

At a Glance

Specification	Detail
Product type	KNX Radio Time Switch, MDRC
Order code	FW/S8.2.1
Product ID	2CDG120039R0011
Channels	8 programmable time channels
Antenna	Optional FAD/A1.1 (DCF/GPS)
Width	3 MW
Supply	110–240 V AC + KNX

Installation instructions, ETS .knxprod, drawings, EPLAN, and declarations are under Downloads.

Applications

• Building schedule: Central time for lighting and HVAC enable.
• Holiday / week programs: Multi-channel calendar logic in ETS.
• Accurate sync: Pair with FAD/A1.1 where radio time is required.

Installation Notes

Mount on a 35 mm DIN rail (3 MW). Connect KNX and 110–240 V AC per the connection diagram. Import the FW/S8.2.1 .knxprod from Downloads. Optional antenna wiring follows the FAD/A1.1 instructions.