Fermax
Spanish Video Door Entry — VDS 2-Wire Bus with KNX 1490 Interface Module
Fermax (Valencia, Spain, founded 1953) is Spain's largest video door entry manufacturer — the VDS (Video Door Switching) 2-wire system is installed across Southern Europe and the Middle East. The 1490 KNX interface module bridges VDS bus events (door call, door open, privacy) to KNX group addresses for lighting and access automation. The newer Fermax Way hybrid system adds SIP over Ethernet alongside VDS bus.
Role in our panels
How we use Fermax
The Fermax VDS 2-wire bus is a proprietary analogue bus system carrying 18V DC power, analogue video, audio, and data on a single YCYM cable (minimum 0.5mm2, maximum 100m from switchboard to monitor without repeater, 200m with BOOSTER repeater module). The VDS bus is a secondary wiring system — all components connect in parallel to the YCYM cable run from the switchboard (GES/GEF series) to each apartment. The switchboard provides 18V DC bus power and manages call routing to monitor addresses. No additional 230V power supply is needed at the door panel or monitor — bus-powered throughout. The 1490 KNX interface module connects in parallel on the VDS secondary bus output from the switchboard. Wiring: VDS A/B terminals on the 1490 module connect to the same YCYM bus as the monitors; KNX bus (red/black) connects to the KNX TP line. The module is configured via ETS6 — assign an individual address, then map group objects: door call event (DPT 1.001, sends 1 on incoming call, 0 after 30s timeout), door open output (DPT 1.001, receives 1 from KNX to trigger door strike), and privacy mode input (DPT 1.001, suppresses door call tone in apartments when privacy flag is active). The 1490 module monitors all VDS bus activity and reports building-level events — it does not differentiate between individual apartment calls. For multi-tenant buildings requiring per-apartment KNX events, configure DIP switch addresses on each VDS monitor (addresses 1–20 via rear DIP switch). Add a Fermax relay module (REL series) to each monitor for a volt-free contact output on call ring — wire the relay output to a KNX binary input module (MDT BE-08.01 or similar). This per-monitor relay approach provides per-apartment KNX call events (e.g. apartment 5 call → KNX binary input 5 → GA for apartment 5 entrance light). Combine with the building-level 1490 module for door open control and privacy mode. The Fermax Way hybrid system integrates VDS bus infrastructure with SIP over Ethernet. The Way door station connects to both the VDS bus (for legacy monitor compatibility) and Ethernet (for SIP and REST API). The Way switchboard routes SIP calls to iOS/Android apps via Fermax cloud or local SIP PBX. REST API door open command from KNX logic (via IP relay or Home Assistant) allows KNX-commanded door release without relay wiring to the door strike. In new-build projects with Fermax Way, the 1490 KNX module remains useful for door call event detection (triggering entrance KNX lighting scenes) while the Way REST API handles door open commands from KNX.
KNX integration via 1490 interface module — VDS door call and open events mapped to KNX DPT 1.001 GAs for entrance lighting, HVAC occupancy, and privacy mode control. Fermax Way adds REST API door open from KNX logic.
Used in these project types
Fermax products
Key components we install
Fermax Loft VDS Door Panel
Flush-mount VDS door panel: 1-button call, colour camera (120° FOV), IP54, night vision IR, stainless steel vandal-resistant faceplate. Bus-powered from VDS 18V DC. Compatible with all Fermax VDS switchboards and monitors. Standard in Spanish residential apartment buildings. Flush box (ref 9549) sold separately. Not compatible with non-Fermax VDS systems.
Fermax 1490 KNX Interface Module
KNX TP interface module for VDS bus: parallel connection on VDS bus, DIN-rail mount, ETS6 configuration. Group objects: door call (DPT 1.001 output), door open (DPT 1.001 input to trigger door strike via VDS), privacy mode (DPT 1.001 input). Reports building-level door call and open events — does not differentiate per-apartment calls. Required for KNX entrance lighting automation triggered by Fermax door station call.
Fermax 6231 VDS Switchboard
VDS switchboard for small apartment buildings: 1 entrance, 4 monitor addresses (expandable to 20 with address modules), 18V DC bus power, 230V AC supply, DIN-rail mount. Manages call routing from door panel to addressed monitors, door strike relay output (12V DC or dry contact configurable), bus power supply. Compatible with 1490 KNX module on secondary bus output.
Fermax MDS 4.3-Inch Colour Monitor
4.3-inch colour TFT monitor: hands-free video call, door open button, melody selection, do not disturb, VDS bus-powered (no 230V required). DIP switch address setting (1–20) for per-apartment identification. Compatible with optional REL relay module for per-apartment KNX binary input integration. Standard monitor for Spanish residential and Southern European apartment buildings.
Fermax Way Hybrid Door Station
Hybrid door station combining VDS bus compatibility with SIP over Ethernet: connects to existing VDS bus (backward compatible with legacy monitors) plus Ethernet for SIP and REST API. REST API door open command allows KNX logic to release the door strike via IP without relay wiring. Fermax cloud or local SIP PBX for smartphone call forwarding. Recommended for new builds or VDS retrofit where smartphone app access is required alongside KNX 1490 module integration.
Fermax FAQ
Is Fermax VDS compatible with Comelit VDS?
No — Fermax VDS and Comelit VIP use incompatible proprietary 2-wire bus protocols. Although both systems use a single YCYM cable, the modulation, addressing, and signalling protocols are different. Mix only same-brand bus components on a single VDS installation. The 1490 KNX module is Fermax-specific and works only with Fermax VDS bus. For buildings mixing brands, use IP-based systems (SIP) with separate IP infrastructure for each brand's devices.
Can the 1490 KNX module detect which apartment was called?
No — the 1490 module reports only building-wide door call events (any call on the VDS bus). It cannot differentiate which apartment address was called. For per-apartment call detection, use the Fermax REL relay module fitted to each MDS monitor — the relay activates on that monitor's call ring and is wired to a dedicated KNX binary input channel. With 20 apartments, this requires 20 relay modules and a KNX binary input module with sufficient channels (e.g. two MDT BE-08.01 providing 16 inputs, plus one additional 8-channel module for the remaining 4).
Fermax Way vs traditional VDS for new builds?
Fermax Way is recommended for new builds — the SIP integration provides a smartphone app for residents (call forwarding when away from home, remote door open) without an additional cloud gateway or complex SIP PBX configuration. The Way door station maintains VDS bus backward compatibility, so existing VDS monitors remain functional alongside the smartphone app. Traditional VDS remains the correct choice for retrofit projects where existing 2-wire wiring is being reused and smartphone app access is not required. Both configurations work with the 1490 KNX module for building automation integration.
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