DALI V2 Multi-Master on the ET 200SP backplane
The Siemens 6ES7137-6CA00-0BU0 is a DALI V2 Multi-Master communication module that slots into the ET 200SP distributed I/O system, giving a SIMATIC controller direct control of a DALI lighting bus — up to 300 m of cable run, with 16-byte input and 16-byte output data exchange per module. It runs on the standard 24 V DC backplane supply, drawing 92 mA typical (250 mA max), and dissipates 1.7 W typ — a low thermal footprint that keeps the enclosure's cooling budget tight even when several modules neighbour it on the DIN rail.
DALI bus interface and diagnostics
The module conforms to DALI V2 Multi-Master (IEC 62386), supporting LED modules (device type 6), absolute input devices, and general operating/input devices on the same bus. Short-circuit detection on the DALI bus is built in, with a diagnostic alarm and an ERROR LED for fault isolation. Two green LEDs — Receive RxD and Transmit TxD — give a live traffic read at a glance, and a presence detector confirms the module is seated and powered. The light sensor and pushbuttons on the front face support commissioning and on-site bus testing without a laptop. Firmware updates can be applied in the field, and the module supports I&M data (I&M0 to I&M3) for asset tracking and maintenance records — useful when the same DALI segment serves multiple zones and the plant MES needs to log which module last saw a bus fault.
Vertical installation is rated from -30 °C to 50 °C ambient, covering most indoor panel environments. The type-test isolation between the backplane and the DALI bus means the lighting circuit can be on a different protective earth reference without coupling faults into the PLC logic. Reverse polarity protection on the supply input and the ability to switch off the DALI bus output via software give the commissioning engineer a clean way to isolate the lighting segment during testing without pulling the base unit.
RoHS conformity is declared. The module carries CE marking and is designed for use in CE-regulated industrial environments.