„Aktor M ST L Modbus“
Technical description
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101274584-V01.11.2019
3. Technical description
3.1 Construction
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71
62
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M30x1,5 DIN 13
Illust. 1: Side view
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1
Illust. 2: Front view
(1)
Push button for releasing the latched valve
stem
3.2 Functional description
The full range of functions will only be available
after parametrization of the Modbus.
Mini actuator Modbus for steady control in heating,
ventilation and air conditioning systems.
Control is carried out via Modbus RTU communica
-
tion (RTU: Remote Terminal Unit).
Apart from the communication on the Modbus, two
universal inputs (binary and analogue) are available.
One of the inputs can be used as analogue output.
The inputs are suitable for internal functions and for
further processing of data in an automation station
(Modbus master).
3.2.1 Basic functions
Automatic recognition of neutral point
The neutral point is detected during the initialisation
run. A cyclical reinitialization is performed during
operation.
Positioning
The actuator is operated with steady control. The
control signal (0..100%) is transmitted via Modbus
communication.
The current position (0..100%) can be queried via
Modbus.
Valve anti-blocking function
The actuator features a valve anti-blocking function
which can be activated. The cycle time can be con
-
figured via the Modbus parametrization.
If the value is zero, this function is deactivated.
The valve anti-blocking function will prevent sticking
of the stem if the valve is not activated over a longer
period.
Setting of valve characteristic lines
Different valve types with their characteristic lines
can be selected via the Modbus parametrization. A
minimum and a maximum volume flow are defined
on the basis of these characteristic lines.
Configuration of the hydronic balancing values
A maximum volume flow (hydronic balancing) for the
heating and cooling mode can be defined via the
Modbus parametrization.
Temperature detection
The temperatures of the supply and return pipe can
be detected via two connected temperature sensors
and can be queried via Modbus.
Flushing function
The actuator features an automatic flushing function.
During flushing, the valve is be temporarily fully open.
