Integration possibilities of iSMA-B-AAC20

AAC20 integration possibilities

iSMA-B-AAC20 device is a fully programable controller based on the Sedona Framework. It can be used with iSMA Tool, a dedicated software that is extremely similar to the Niagara Workbench and is free to use. IBC’s engineer Szymon Drozdek presents one of iSMA’s more advanced and feature rich controllers and uses practical examples to illustrate the integration possibilities of iSMA-B-AAC20.

Take a closer look at the integration possibilities of iSMA-B-AAC20

The AAC20 has a very interesting feature, which is not always immediately highlighted within the documentation or undertakes iSMA training. Because the device supports so many protocols (BACnet IP/MSTP, Modbus TCP/RTU/ASCII, Mbus or DALI, SOX, oBIX, 1-wire) the question that might appear is about integration possibilities between these different protocols. Is it possible to integrate the AAC20 into all these different protocols? The answer is yes, it’s possible. What is more, it is possible in really easy and convenient way without third-party hardware involved.

Sedona/Niagara frameworks wins on the market, because of integration possibilities. Building Automation System can consist of multiple communication protocols, which demand an integration process. The integration usually costs both additional hardware (routers, gateways) and engineering time. Sedona solves this challenge by introducing N-1 Architecture, which assumes that all the data from various protocols can be present in 4 main types of components:

  • Boolean (1-0, digital signal)
  • Numeric (integer, float, value)
  • String (text)
  • Enum (multistate, f.ex. HOA signal)

The data normalization makes the system independent from network interfaces exist on the project. What is more, it allows to omit additional hardware commissioning and reduces necessary integration to minimum – installing appropriate software driver which specifies how data from particular device is mapped into standard Sedona Objects.

Here’s how it works – AAC20 integration step by step

First, let’s try to make software connections between BACnet Local Device (IP) and BACnet MSTP device (RS485). In the iSMA Tool Software there are two networks added: BACnet Network and BACnet MSTP Network. The “Local Device” component under the BACnet Network represents AAC20 device itself, available on BACnet IP. The component “Device” under the Remote MSTP Network represents any BACnet device connected to the RS485 port built-in the AAC20 device. Each device has Analog Value component added. To make connection between them we invoke command “Link Mark” (right-click) on the source component (AV on the “Local Device”). Then we invoke command “Link From” on the target component (AV on the “Device”).


iSMA tool workspace

Picture 1. Link Mark command on the source.











iSMA Tool screenshot

Picture 2. Link From command on the target.











In the pop-up window we need to select proper slots to be linked. In most cases is the OUT and IN10 slots in case of Analog Value component type.

iSMA Tool AAC20

Picture 3. Linking the Slots.













After clicking the OK button we can see that the link is created.

iSMA Tool link path

Picture 4. The Link path.













The final result of the procedure described above is connections between components assigned with different interfaces (IP and RS485). In fact, the AAC20 application works as a BACnet Router between IP and MSTP layer.

Exactly the same procedure needs to be done in case of the other protocols.

The examples below present the connections between Modbus IP and BACnet MSTP (Picture 5.) and BACnet IP and Modbus RTU (Picture 6.). The user can link together components from the different protocols in any configuration. It is worthy to keep in mind that only one protocol can be active on RS485 interface at the same time!

Modbus IP to BACnet MSTP integration

Picture 5. Modbus IP to BAcnet MSTP integration.

BACnet IP to Modbus RTU integration













Picture 6 BACnet IP to Modbus RTU integration.

AAC20 Specs

The AAC20 has 22 I/O on board (8xUI, 4xDI, 4/6xAO and 4xDO). It can be ordered in different options: with LCD, additional Mbus or DALI interface. The controller supports Modbus and BACnet (BTL certificate – AAC), both through RS485 and IP. The Built-in web server allows to configure communication and local I/O as well as diagnostics. To collect alarms and trend logs the AAC20 has RTC and SD Card provided. The device is powered by 24 VAC/DC. The application programming based on pack of the kits is provided by the manufacturer Global Control 5 (GC5). The different components need to be linked together to create logical connections between I/O, network variables etc. Advanced users can develop their own kits using JAVA based language. Sedona Framework is open and provide all recourses needed.

Have questions?

IBC’s BMS engineer Szymon Drozdek, formally of GC5, can guide you through all iSMA solutions and processes. Contact Szymon by email at [email protected]