The ABB PMH/U2.1.1 Presence Detector HF KNX Basic is a 360° ceiling presence sensor using 24 GHz radar. Unlike PIR, it can detect small movements (including through drywall, wood, and glass) and is less sensitive to temperature swings. Choose white matt or black matt below.

This IP20 Basic model has 2 KNX channels, an integrated bus coupler, and brightness, temperature, and humidity sensors with KNX Data Secure. For 4 channels, constant-light control, RTC, and 5 logic channels see PMH/U4.5.1 Premium. The 5.8 GHz movement sister is BMH/U2.1.1.

Key Features

• 24 GHz HF radar: Presence detection with reduced wall penetration vs 5.8 GHz BMH — sharper indoor coverage.
• 2 KNX channels: Constant-light switching and brightness-dependent lighting.
• Climate sensing: Brightness + temperature + humidity on the same device.
• KNX Data Secure: Secure commissioning for modern KNX installs.
• Flexible mounting: Recessed Ø 68 mm, or PMA/A1.1 surface / PMA/K1.1 BS / PMA/K2.1 VDE.
• 2 finishes: White matt (−884) and black matt (−885).

At a Glance

Specification	Detail
Product type	KNX HF presence detector, 360°, Basic, IP20
Order family	PMH/U2.1.1-88x
Technology	24 GHz HF radar
Channels	2
Sensors	Brightness · temperature · humidity
Detection (circular)	Ø max. 8 m @ 2.5 m · 10 m @ 3.0 m · 8 m @ 4.0 m
Finishes	White matt (−884) · Black matt (−885)
Protection	IP20
Bus system	KNX TP · Data Secure

Color / Order Codes

Finish	Order code	Product ID
White matt	PMH/U2.1.1-884	2TYZ510202G0601
Black matt	PMH/U2.1.1-885	2TYZ510202G0701

Product manual, installation instructions, EPLAN, and CAD/BIM are under Downloads.

Applications

• Offices & meeting rooms: Presence + constant-light switching with climate feedback.
• Rooms with partitions: 24 GHz still sees through light materials; use BMH 5.8 GHz when deeper penetration is required.
• Premium upgrade: RTC, 4 channels, and logic on PMH/U4.5.1.

Installation Notes

Cut a Ø 68 mm ceiling hole for recessed mounting, or use PMA surface / BS / VDE kits. Connect KNX via the integrated bus coupler (no auxiliary mains). Commission detection range in ETS; follow the product manual in Downloads.