Adding BACnet Parameters¶

A BACnet parameter maps one point (object) of a controller to a trackable data point in Enture. Once added, the platform reads the point continuously — and writes to it, if you set it up for that — and makes the value available for dashboards, reports, alerts, and real-time views.

Before you begin¶

• The BACnet Device must already exist.
• You need the object type and object number (instance) of each point, as listed in the controller's point list or its BACnet documentation. For example, "Analog Input 3" is the object type Analog input with object number 3. You do not need them if you read the point list from the controller.
• You need Engineer access to create parameters.

There are three ways to add parameters: one by one (the steps below), by reading the point list from the controller, or by importing a CSV or EDE file.

Steps¶

1. Open the BACnet Device¶

In the left sidebar, go to Digital Twin → Devices and open the device you want to add a parameter to.

2. Add a parameter¶

Click Create BACnet parameter.

3. Fill in the parameter details¶

The value type follows from the object type: analog points are numbers, binary points are on/off (1/0), and multi-state points are state numbers (1, 2, 3, …).

4. Common settings¶

Correction Factor, Idle Latency, Entropy, and the related checkboxes (Enable Entropy, Limit Entropy, Remove Negative Entropy, Remove Decimal, Restrict User Access, Calculate Consumption, Disabled) work the same way as on every other protocol — see Common Parameter Settings for details. For BACnet the Correction Factor can be any number except 0.

5. Save¶

Click Create. The parameter is added to the device.

Each point on a controller can be added to a device only once.

Reading the point list from the controller¶

The edge device can read the controller's own list of points, so you pick points instead of typing them. This only reads: nothing on the controller changes.

1. Open the device and click Create BACnet parameter.
2. Open the Discover tab and click Read point list. On a large controller this can take up to a minute.
3. The points Enture can read are listed with their name, object type and number, unit and description. Points already added to this device are marked Already added. The list also says how many objects of other types (for example schedules or trend logs) were left out.
4. Tick the points you want. Use the search box to find points by name, type, number or description.
5. Choose Access for outputs and values: Read only (default) or Read and write. Input points are always read only, and you can change any point later.
6. Choose the Read mode for the picked points: Polling (default) or Change of value (COV) — see Change of value (COV).
7. Click Review points. The points open in the CSV upload tab, where you can set the shared settings (for example the read interval), see every point checked, and create them all at once — exactly as for an uploaded file (see below).

The unit is filled in from the unit the controller reports. Names longer than 40 characters are shortened.

Importing points from a CSV or EDE file¶

Open the device, click Create BACnet parameter, open the CSV upload tab and drop the file. Every row is checked before anything is created, and points already on the device are reported as duplicates.

CSV file. Click Download template for an example. The columns are:

EDE file. An EDE file is the point list that most building management tools can export (Engineering Data Exchange). Drop it as it is: Enture takes the points of this device (matched by its device instance) and leaves out points of other devices and object types it does not read; a note above the preview says how many. Each point gets its name, object type and number, description and unit from the file; points marked settable become Read and write (inputs always Read only). Names longer than 40 characters are shortened.

Change of value (COV)¶

With Polling, the edge device reads the point every few seconds, whether or not the value changed. With Change of value (COV), the edge device asks the controller to report the point itself whenever its value changes, so changes appear in Enture at once and the network carries less traffic.

• While the controller is reporting changes, the edge device still reads the point once a minute (or at its Read every interval, if that is longer). This keeps the value up to date on screen when nothing changes, and notices if the controller stops reporting.
• Not every controller supports COV for every object type. If a controller refuses, the point is simply polled at its Read every interval, and COV is tried again about every 10 minutes. You do not need to do anything.
• If the controller cannot be reached, the point is polled as usual, and COV starts again once the controller answers.
• Each COV point uses one of the controller's subscription slots, and controllers only have a limited number of them, which the building management system may also need. Choose COV for the points where fast updates matter (alarms, run status, setpoints that change), and keep polling for the rest.
• How small a change the controller reports for analog points is set in the controller itself (its COV increment), not in Enture.

Write priority¶

BACnet controllers rank the commands they receive on a scale from 1 (strongest) to 16. When several commands are active on the same point, the controller follows the strongest one. This has two consequences for you:

• A value you write is overridden by any stronger command — for example from the building management system. The point then keeps the stronger command's value, even though your command was accepted. Always check the live value to see what the controller is actually using.
• A value you write stays in force until you release control (see below) or something stronger takes over.

Choose the level your commands should use when you set the point up:

• 8 is the usual level for a person at a console, and is the default.
• Levels 1, 2 and 6 are reserved — 1 and 2 for life-safety functions, and 6 for the controller's own minimum on/off timing — and cannot be selected.
• Use a smaller number (3–5, 7) only if you want your command to win against more of the building system's own commands.

Writing a value or releasing control¶

A point shows a write area on its detail page when it is set to Write only or Read and write, writing is enabled for the parameter, and you have the Write permission.

Sending a value¶

1. Open the parameter's detail page (click the parameter name on the device).
2. In the Write area, enter the value:
   • Analog points — type a number.
   • Binary points — click On or Off.
   • Multi-state points — type the state number (1 or higher).
3. Click Send.

Enture first confirms that the command was sent. Below the write area, it then shows Waiting for the hub to confirm… until the edge device reports what happened, usually within a few seconds.

Reading the result of a write¶

Once the edge device has written the value and read the point back, the write area shows one of these results, with how long ago it happened:

The last result stays visible for about 10 minutes, so you also see it if you open the parameter just after someone else wrote to it.

Releasing control¶

Writing a value never gives control back by itself. To hand the point back to the building system, click Release control. Your command is removed, and the point returns to whatever the controller's own logic or a weaker command dictates. The result area then shows the value the controller is using after the release.

Switching writing on or off¶

When you add a point as Write only or Read and write, writing is switched on. A user with engineer access can switch it off and on again with the Disable Write / Enable Write button on the parameter's detail page — useful as a quick safeguard while maintenance is in progress. Changing the point's other settings does not switch writing back on. A point set to Read only can never be written, and writing cannot be enabled for it.

What happens next¶

The edge device receives the updated parameter list within approximately 30 seconds and begins reading the point.

Viewing live data¶

1. Navigate to Digital Twin → Devices → open the device.
2. Click on the parameter name.
3. The parameter detail page shows the current value and a real-time chart.

Updating or deleting a parameter¶

On the device, use the edit and delete actions on the parameter. An existing parameter's device cannot be changed.