Tridium: How To Configure a BACnet Server Driver and Export Points

This article will serve as a guideline for configuring a new BACnet server driver for a Tridium Niagara AX platform. The BACnet server is necessary for integration of room reservation schedules from Events2HVAC and HVAC devices on the Tridium network. E2H communicates via BACnet/IP to send commands modifying zone occupancy states. The BACnet server driver allows the Tridium system to export out Tridium point objects and expose them as BACnet objects.

For the purposes of this article, it is assumed that the client or integrator with the Tridium system uses another protocol (e.g. LON), and no BACnet drivers are loaded.

The following steps will guide you in configuring your server for point export.

For detailed procedures, refer to Technical Document - Niagara AX-3.x BACnet Guide

Step 1: Load the driver

If you haven't done so already, acquire the Tridium BACnet Server driver and install it on your Supervisor or a JACE. You can check your license file to see if the driver can be used as a BACnet server. If you see export="true" in the BACnet license, then you have both client and server capability. Also, if you ordered your JACE with the "Enterprise Connectivity Pack", your license should include the BACnet server.

Refer to Niagara documentation on how to install drivers.

Step 2: Add a BACnet Local Device

Add a new BacnetNetwork in the Driver Manager.

Step 3: Configure the Local Device

Right-click on the new "BacnetNetwork" and select Views > Property Sheet.
Expand Local Device and assign an Object Id for the local device ID of the BACnet server. This number needs to be between 0 and 4194302 and cannot be the same as that of any other existing BACnet device. (a value of -1 disables the BACnet device)
Verify that after saving the local device, the Status should be {ok}

Figure 1 - Active Local Device Parameters

Step 4: Config the BACnet/IP Port

If you don't see an IP port under Bacnet Comm, you will need to add a new BACnet/IP port to your NetworkPorts folder.

Set the Network Number from "-1" to the BACnet network number for the network segment you are connecting. If you have existing BACnet devices, get this number from someone who is familiar with the system. If this is a new network, just use "1". Valid network numbers are from 1 to 65534.
Expand the Link component in the property sheet.
Under Link, use the drop-down list for the network adapter to select BACnet/IP.
In IP Device Type, select Standard. If Events2HVAC is on a different subnet than the Tridium local BACnet device, and there are no other BACnet devices on your subnet, then you may need to select BBMD (BACnet Broadcast Management Device) instead.
Set the UDP port to be used for BACnet communications. By default this is 47808 (0xBAC0 in hexadecimal).
Click Save.
Right-click the IP Port (in property sheet or Nav side bar), and select Actions > Enable. Verify the Link Status = {ok}.

Only one BBMD device can be defined for each BACnet subnet!

Figure 2 - BACnet/IP Port Configuration

Step 5: Allow Write Access

When the BACnet server driver is installed, a "BACnet" user is created with readOnly access. Now, any external client can read any of the devices and objects exposed by the BACnet driver. To allow an external client write access, you will need to give this user write permissions.

Figure 3 - Default "BACnet" User Properties

Step 6: Export Points

The next step is to export out all the control points in Tridium that you would like to expose as BACnet objects. This is done in Tridium using the Bacnet Export Manager.

You can export points as BV, BO, Schedule, or Calendar objects, depending on how you want to integrate your zones with Events2HVAC.

At this point you can use the Discover feature to find a list of Tridium points that you want to export. You can also add points manually. The points created will be the BACnet objects that E2H will send commands to, so it is up to the integrator to determine what points need to be written to. Also, when selecting what type of BACnet point to export, you must use types that are Writable, Bacnet Binary Value Prioritized, for example. For writable points, you must also select what priorities are available to write to.

After all desired points are exported, you can view them in your Local Device > Export Table,

Figure 4 - Exported Point Properties

Note that the Object Name and Description fields can be modified to be more meaningful to other external BACnet clients.

If exporting Niagara schedule objects to BACnet, you must also export any calendar object references that are attached the the schedule objects.

Step 7: Verify Discovery

Now your Tridium JACE or Supervisor should be broadcasting as a BACnet device, and if you were to run the BACnet Explorer tool in E2H you should be able to see the Tridium local device. You should also see all of the exported points as well.

Device Properties as seen from the BACnet Explorer:

Figure 5 - Device properties as seen from BACnet client

If the Tridium device is not visible, there may be something blocking BACnet UDP traffic. Ensure the following:

Make sure you can ping the Tridium server from Events2HVAC.
Make sure UDP port 47808 traffic (or traffic for whichever port is configured) is allowed to pass between Events2HVAC and the Tridium server. You may need to add inbound port firewall rules to allow this or turn Windows firewall off.
If Events2HVAC is on a different subnet than the Tridium server, Events2HVAC will need to connect as a remote foreign client to a BBMD on the BACnet network. If one doesn't exist, you can change the IP Device Type to BBMD (from Standard) in the BACnet/IP Link properties of the Tridium BACnet Server.