UserManual AIAS201910

4/24 | User Manual AIAS | 201910 201910 | User Manual AIAS | 5/24
Detailed Topology
The operation of AIAS optimizing system is based on the reading of the position of the VAV controller dampers.
The damper position information can be transmitted in two different ways:
1. Analog signal (DC 0-10 V or 0-10 kOhm)
These signals are collected in AIAS RIO (remote input/output) module and transferred to AIAS Combox via Exoline
communication bus. There can be two RIO modules each with 16 analog inputs used for one Combox. That
means, up to 32 VAV damper position signals.
This method is recommended, if the VAV controllers in the system are not able to communicate via bus. Especially
in case of refurbishment, where older VAV´s have only 10V position signal or even none, their replacement is not
required. The VAV´s without position signal can be equipped with auxiliary angle position sensors with 10kOhm
potentiometer and integrated so in AIAS optimizing system.
2. Modbus RTU communication
Systemair VAV controllers with Modbus RTU communication ability (controller type BLC-MOD) can share the
position information via Modbus directrly to AIAS. Also other VAV operational variables can be communicated via
Modbus.
Both of these modes allow to integrate also VAV controllers operating in master/slave combination of air supply
and extract (balancing the room pressure) where each of them belongs to the optimizing loop of corresponding fan
(supply VAV to supply fan and extract VAV to extract fan).
Also these modes sllow to integrate the zone balancing VAV´s on both, supply and extract side of the ventilation
system.
Even though no additional digital controllers except AIAS Combox are necessary for optimizing functionality, the AIAS
system can handle useful functionalities performed by room controllers AIAS RC. Besides the individual room control
functions like room temperature control, combinable with control of other values (CO2, humidity etc.) and besides the
local overrides (occupancy sensor, window contact etc.) the AIAS can add the centralized remote functionalities like
heating/cooling change-over, free cooling, common overrides. These are effective centrally for all connected room
controllers.
The fan power control by AIAS Combox (master) is based on sending DC 0-10V setpoint signals to the fan power
control units (frequency converters or other controlled power limiters) – separately one to the air supply and one to
the air extract unit.
The connection for fan power control signals between AIAS Combox and the air handling units (Topvex or DV by
Systemair, using the „frequency control external“ conguration in DDC with corresponding analog inputs conguration
„external control SAF“, „external control EAF“) or fans can be seen in wiring diagram of AIAS Combox (page 10). In
some AHU´s it is possible to use pre-congured analog inputs of the AHU control unit for auxiliary control of the fan
speed by AIAS. The AHU´s and fans without this option can be connected directly. That means, that the fan power
control signal from standard AHU or fan controller will be disconnected from the fan frequency converter or other
controlled power limiter. At the same place (input terminals) the control signal from AIAS will be connected.
If the AIAS Combox is in a chain of more Combox controllers, it reads the fan power setpoint signals from the controller
1 level lower in the chain. It compares these signals with own calculated setpoints and sends out the higher demand
signals to the controller higher in the chain. The higher controller does exactly the same and so the highest demand
singnal propagates to the fan control. So the AIAS comboxes in the chain do not need to communicate the fan power
demand on any bus – the connection of analog inputs and outputs is easy and without any additional conguration.