Copyright Micropelt
General Description MLR003R
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3 General Description MLR003R
This document defines the properties of Micropelt’s maintenance free, intelligent thermostatic head
MLR00RiEU61-07-1.1. This MLR003 is used for control of heating radiators with standard valve connection
M30x1.5 (Section 10).
MLR00RiEU61-07-1.1 is an 868MHz LoRaWAN CLASS-A wireless actuator operating in SF7BW125.
LoRaWAN end-devices of Class A allow for bidirectional communications whereby each end-device’s
uplink transmission is followed by two short downlink receive windows. The transmission slot scheduled
by the end-device is based on its own communication needs with a small variation based on a random
time basis (ALOHA-type of protocol). Class-A operation is the lowest power end-device system for
applications that only require downlink communication from the server shortly after the end-device has
sent an uplink transmission. Downlink communications from the server at any other time will have to
wait until the next scheduled uplink. SF7 is using the shortest time-on-air to maximize the number of end
nodes operating on one gateway.
Each standard production MLR00RiEU61-07-1.1 unit has a unique DEVEUI, APPEUI (JOINEUI) and a
randomly generated APPKEY. Device credentials are secret and will only be submitted with the product
delivery. Questions related to device credentials can be sent to
To operate the device, the unit must be paired with a compatible controller or gateway unit supporting
its communication profile (Section 7). The pairing is done as described in Section 8.3. Once mounted and
activated on the valve body using the magnetic key, a calibration cycle starts to automatically adapt
itself to the individual valve. Then it is ready for use. Adapters are available for a majority of non-M30x1.5
valve bodies.
Success of activation or deactivation is signaled by tone signals and LED (Section 8.1).
The product is delivered in mounting position (off) with the valve plunger completely retracted. When
operating, the unit recognizes if it is installed on a valve body by means of internal force and travel
distance measurement. The device has built-in motor error detection "ME". The ME bit signals motor
issues during normal operation.
The actuator operates with a communication profile as further specified in Section 11. The default radio
communication cycle is 10 minutes. Installation, activation and a successful join with the network server
will immediately set the radio communication interval to every 10 seconds for an installation period of 5
minutes to provide rapid feedback. Temperature values are transmitted in both raw and corrected
temperature formats.
The actuator has a built-in, valve-side temperature sensor to determine the flow pipe temperature. A
controllable offset of +5°C has been added to compensate for the temperature drop between the hot
water and the sensor element located in the actuator’s aluminum valve adapter.. The device transmits a
variety of information to the control unit by sending an uplink (Section 7.1). The control unit responds by
sending a downlink (Section 7.2).
The integrated valve side temperature sensor is also used for freeze protection. Freeze protection is
activated at <=6°C.
The ambient sensor is used to measure the room temperature. During heating operation, the ambient
sensor is influenced by self-heating of the metallic device housing. The algorithm used to estimate the
actual ambient temperature is described in Section 12.9.
