SALTO and ASSA ABLOY Online Door Systems: KNX Integration via OSDP and BACnet
SALTO and ASSA ABLOY represent two major European access control platforms with distinct integration paths to KNX. SALTO XS4 offers BACnet/IP as an optional module and SHIP as a proprietary protocol, while ASSA ABLOY brands including HID Global support OSDP v2 and REST API bridging. Selecting the correct integration path depends on the platform version, building type, and whether an existing BMS or KNX controller is present.
SALTO XS4 online platform and KNX integration paths
SALTO Systems, based in Spain, produces the XS4 online access control platform widely installed across European commercial offices, hospitals, and universities. Two KNX integration paths exist for SALTO XS4 online installations:
The SALTO SHIP (SALTO Host Interface Protocol) is a proprietary IP protocol for third-party integration. Use the SALTO SHIP server middleware to bridge events to Node-RED or a custom KNX integration script. SHIP provides door state, access events, and cardholder data in real time over TCP/IP.
SALTO BACnet/IP module — KNX bridge via LOYTEC LGATE-950
SALTO XS4 with optional BACnet/IP module installed: Exposes door states and access events as BACnet objects BI (Binary Input): door open/closed state per door BI: last access granted (pulsed, 1s ON per event) AV (Analog Value): access count (resets daily) LOYTEC LGATE-950 BACnet/IP to KNX gateway: Configure LGATE-950 as BACnet client SALTO BACnet server IP: <salto-server-ip> port 47808 Map BACnet BI:1 (door open) → KNX GA '2/0/1' DPT 1.001 Map BACnet BI:2 (access granted) → KNX GA '2/0/2' DPT 1.001 In LGATE-950 L-STUDIO configuration tool: Add BACnet device (SALTO server IP/port) Read BI objects → assign to LGATE data points Map data points to KNX group addresses Set poll interval: 1 second for door state GAs KNX floor plan display (MDT SCN-IP000.03 IP interface): GA 2/0/1 drives door open/closed indicator on touchpanel
Important — SALTO SVN offline limitation: SALTO SVN (Space Virtual Network) offline readers store access permissions on the card itself — there is no online connection to the reader. For KNX integration in real time, only SALTO XS4 online readers with Ethernet connectivity work. Verify with the installer whether the existing SALTO installation is SVN offline or XS4 online before specifying a KNX integration project.
ASSA ABLOY platform overview and HID Global OSDP readers
ASSA ABLOY is the largest access control company globally, encompassing multiple brands: Yale Nexus IP (UK and Europe), HID Global (credential technology), and ASSA ABLOY Opening Solutions. For KNX integration, the primary paths are HID Global OSDP v2 readers at the reader layer, and the ASSA ABLOY ARCOS IP-based access server at the management layer.
HID Global OSDP v2 reader — Beckhoff TwinCAT integration
Hardware setup:
HID RP40 or RM40 multi-technology reader (OSDP v2)
RS485 wiring: reader A/B to Beckhoff EL6700 RS485 terminal
Beckhoff CX9020 with EL6900 KNX EtherCAT terminal
TwinCAT configuration:
EL6700: OSDP master mode, baud 9600, address 1
Install Beckhoff TE6730 OSDP function library
TwinCAT PLC Structured Text:
OSDP_ReadCardNumber(fbOsdp, nCardNumber => wCardNum);
IF wCardNum = CARD_SERVER_ROOM_1 THEN
KNX_Write(GA := '9/0/1', bValue := TRUE); // door open KNX
KNX_Write(GA := '9/0/2', bValue := TRUE); // HVAC occupied
END_IF
OSDP bidirectional: write LED colour back to reader
KNX access granted GA → EL6700 → reader LED green
KNX access denied GA → EL6700 → reader LED red
Provides visual feedback to cardholder at readerASSA ABLOY ARCOS REST API integration
The ASSA ABLOY ARCOS platform provides an IP-based access management server with a REST API. The integration pattern is identical to the Gallagher Command Centre REST API approach — OAuth2 authentication, event polling or webhooks, and a Node-RED bridge to KNX. This makes ARCOS one of the most straightforward ASSA ABLOY platforms to connect to KNX.
ARCOS REST API to KNX — Node-RED flow structure
Authentication:
POST /arcos/api/v1/auth/token
Body: { "clientId": "...", "clientSecret": "..." }
Returns: { "token": "Bearer ...", "expiresIn": 3600 }
Event polling:
GET /arcos/api/v1/events?since={timestamp}&limit=50
Authorization: Bearer {token}
Returns: array of access events (same structure as Gallagher)
Node-RED flow:
Inject node (5s interval) → HTTP request node (ARCOS events)
→ switch node (filter by eventType and door name)
→ KNX write node (GA based on door-to-GA mapping)
ARCOS also supports webhook push (version 3.2+):
Configure webhook URL in ARCOS admin panel
→ Node-RED HTTP input node receives events in real time
→ eliminates polling, reduces latency to under 500ms
Identical KNX GA scheme to Gallagher integration:
Access granted → lighting and HVAC group addresses
Door forced → alarm relay group addressServer room cooling automation on door open
A practical application for SALTO or ASSA ABLOY KNX integration is server room precision cooling optimisation. When an engineer enters the server room, the door open event triggers a temporary increase in cooling capacity. After the door closes, the system returns to standard setpoint after a stabilisation period.
Server room door event to STULZ precision cooling KNX control
Access granted — server room door (SALTO or ASSA ABLOY):
→ KNX GA 9/0/1 = true (door open event)
→ KNX logic writes STULZ precision cooling setpoint:
GA 9/0/2 = 18 (reduced from standard 20°C — DPT 9.001)
GA 9/0/3 = true (STULZ high-capacity mode via relay)
STULZ CRAC unit with KNX interface (STULZ KNX option card):
Accepts setpoint write on KNX GA
Reduces room temperature during engineer work
Provides additional cooling margin while door was open
Door closed event (SALTO BACnet BI or OSDP status):
→ Start 15-minute timer in KNX logic module
→ After 900 seconds:
GA 9/0/2 = 20 (return to standard setpoint)
GA 9/0/3 = false (disable high-capacity mode)
Energy saving calculation:
Standard setpoint 20°C: STULZ runs at base load
High-capacity mode: only during door-open + 15min window
Avoids continuous low setpoint that would otherwise be
set manually by engineers and forgotten overnightOSDP advantage for compact KNX integrations
OSDP v2 offers bidirectional communication between reader and controller — the controller can display LED colour and text on the reader display, not just read card data. All major brands — Gallagher, Paxton, HID, and ASSA ABLOY — support OSDP v2 on their current reader ranges.
Beckhoff TwinCAT DIN-rail integration — OSDP + KNX + Modbus
Single DIN-rail controller handling three protocols: Beckhoff CX9020 (EtherCAT controller, 24V DIN-rail) + EL6700 RS485 terminal → OSDP v2 reader (access control) + EL6900 KNX TP terminal → KNX bus (building automation) + EL6001 RS232 terminal → Modbus RTU meter (energy) TwinCAT PLC logic integrates all three: OSDP card read → KNX scene trigger KNX binary input → OSDP reader LED command Modbus energy meter → KNX energy GA update Footprint: 6 DIN-rail modules + controller No separate PC server, no additional middleware All logic in TwinCAT Structured Text — fully documented Suitable for: small commercial offices (under 20 doors) with existing Beckhoff KNX panels Most compact solution for combined OSDP + KNX requirement
Practical recommendation: for most KNX projects, a lightweight middleware approach — Node-RED on a Raspberry Pi 4, or an Enertex EibPC — bridging the access system API to KNX group telegrams is the most maintainable solution. Full BACnet integration via LOYTEC or OSDP with TwinCAT is preferred in large enterprise buildings with dedicated BMS engineers who can maintain PLC code. Choose based on the building management team capability and maintenance contract.
Need a KNX panel with SALTO or ASSA ABLOY integration built to spec?
We design and build low-voltage panels with BACnet/IP LOYTEC bridges, OSDP v2 Beckhoff TwinCAT controllers, ARCOS REST API Node-RED flows, and full commissioning documentation delivered tested to your site.
Request a quote →