MVA003E User manual and device specification
Preliminary
April 2019
Page 14 of 24
1DSMVA003E_0419v9e
8.2
Description of individual functions
8.2.1 Setpoint Selection (DB1.2, RCU to MVA003E)
Selection whether A5-20-01 and the actuator is used with Valve Position (Controller running in the
room or building control system) or with its internal temperature control loop.
8.2.2 Valve position [%] and Setpoint temperature [°C] (DB3, RCU to MVA003E)
Setpoint temperature °C: The external radio partner transmits the temperature setpoint for the internal
controller (0 ... + 40°C, DB3.7 ... DB3.0 = 0 ... 255). The use of a separate, external room temperature
sensor is recommended whose room temperature (DB2.7 ... DB2.0) is transmitted to the device by the
room controller as part of the A5-20-01 protocol. The internal controller thus does not use the ambient
temperature measured in the near field of the radiator, but the actual room temperature. When operating
with an internal temperature sensor, DB2.7 ... DB2.0 must be set to 0x00. Values not equal to 0x00 are
interpreted as sent room temperatures and thus lead to faulty control behavior.
Valve positon (%): The external radio partner transmits a 0 ... 100% control signal (DB3.7 ... DB3.0 = 0
... 100) and converts it into an actuating movement by the actuator (0% = closed valve / 100% =
completely open valve).
8.2.3 Summer Mode (DB1.3)
When the actuator receives the status message „Summer mode ON“ from the controller, then the valve
transmit/receive interval is increased 10 minutes to 8 hours. It is possible to wake up the iTRV through
1 x pressing the push button. Then the iTRV receives the new setting from the room controller.
8.2.4 Safety temperature set (DB2.3)
STS is only used when MVA003E is operated in temperature setpoint mode (SPS = 1). Every valid
temperature setpoint (°C) received is internally stored. Apart from standard SPS=1 operation is this
value also used in case of radio loss situations as setpoint for the device internal temperature controller.
The status flag DB2.3 = STS = 1 is only used to acknowledge the successful reception. STS = 0 when
operated in valve position mode SPS = 0. STS=1 will also appear in radio loss situations indicating that
a setpoint value independent from its fixed 21°C safety value is available. STS can be Reset with the
Remote Commissioning command RESET DEVICE DEFAULTS.
8.2.5 Recognition of valve position and reference run
The valve actuator recognizes during the teach-in the closing position of the valve. During operation the
valve actuator does a full stroke (self-calibration) after every 2
nd
week, to avoid malfunction of the valve.
8.3
Example of a radio protocol
Radio protocol of MVA valve actuator
to
Controller /Gateway
Example in HEX "0x32708908"
DB3.7…DB3.0 = 0x32 = 50: valve position is 50%
DB2.7…DB2.0 = 0x70 includes
o
DB2.4 = 1 Energy storage capacity sufficient
o
DB2.5 = 1 Energy storage charged
o
DB2.6 = 1 Energy input enabled (Harvesting active)
