Configuration of the BACnet driver

Open the configuration panel of the BACnet driver via the system management panel to configure the device in WinCC OA.

Figure: System management - Driver tab

Click on the BACnet Driver button.

Configure in the following panel the peripheral device.

Figure: Configuration panel of the BACnet Driver

The configuration panel of the BACnet driver is divided into the following areas.

Device

By a click on the Create button an input window is opened, by what a new BACnet data point can be created (in a redundant project a data point with the name <deviceName+"_2"> is created automatically for the second device). After device creation, the other configuration parameters for the periphery can be set. These are saved in the internal data point  "_BacnetDevice". Select from the combo box the device name, if you want to change the settings. After changing the settings click on Apply or OK to confirm. Once a new connection data point is created this can be used by the driver immediately (no reboot required).

Check the Active check box to set the selected BACnet device active/inactive. You can deactivate a device that is already created and configured. In this case the driver does not communicate with the device. The data point of the device will not be deleted and can be reactivated at any time.

The Remove button removes the selected device.

Common Settings

Enter in the Device Id input field the unique identification number for the BACnet device or use the spin buttons to do so.

Enter in the Password input field an individual password for the BACnet device configuration. This password will be used for the BACnet services (e.g. "DeviceCommunicationControl" and "ReInitializeDevice" - re-initialization of the device). If a password will not be defined, so the password will not be sent to the BACnet device.

Enter in the Alive Iv. input field the time in seconds after whose expiration an alive check for this device should be performed in the network. The default value is 0, whereby the interval is adopted from the deviceStatusPollTimeout config entry (if this config entry is not set, the general default value is 30 seconds). If the alive interval is set to greater than 0 seconds, then the interval is used (only) for this device (per BACnet device configurable). The alive check is carried out using a ReadProperty request.

Note

If the time for the alive check is to high, it may happen that a connection loss will not be recognized early enough what leads to the fact that alarms get lost. This can be avoided by periodical triggering of GetEventInformation (e.g. by a script).

Enter in the Synch Iv. input field the time in seconds, after which an automatic time synchronization of the device is performed. Therefore a static Address Binding must be defined (see further below) in order to trigger a time synchronization directed to the device with the specified IP address. The default value is 0, whereby no directed time synchronization is triggered. A manual time synchronization can be performed using the Time command from the configuration panel. It is only supported for static bindings.

A time synchronisation via broadcast to all BACnet devices in the network can be triggered with the internal data point element _Bacnet_x.Command.SyncTime.

Note

If the BACnet driver can not connect to the utcTimeSynchronization service, the internal synchronisation of WinCC OA is used as fallback.

Click the "..." button next to Alertpriorities to map BACnet priorities to WinCC OA alert classes for the selected device in the Alert Priority Mapping panel. This is only necessary if a different mapping should be defined for various devices, else it is possible to carry out the mapping for a selected internal BACnet driver data point (is valid for all devices), see Alarm priority mapping. As both panels have the same layout, please follow the configuration instructions described there.

Note

A configured alert priority mapping for a BACnet device is used always preferentially than the mapping for a BACnet driver. Otherwise the mapping defined in the driver is used.

Address Binding

There are two possibilities to set the BACnet/IP address for a device - dynamic or statical.

If dynamic is chosen, the address is assigned dynamically. This means that the driver determines the BACnet/IP address from the "I am" telegrams of the BACnet devices.

Note

If in the time between the BACnet device has sent the "I am" message and the update of the Address Binding a command is triggered, this possibly can get lost, as it was sent to the device with the old IP address.

If an IP address of a BACnet device changes and the BACnet driver is started afterwards, the Address Binding is updated automatically, since the BACnet driver triggers a "Who Is" message using the "DM-DDB-A" BIBB and receives the corresponding "I am" messages with the new information.

If static is chosen, the BACnet/IP address has to be allocated by the user - thus, an automatic update is not performed. If there is a change in the information, this has to be updated manually by the user.

The information is:

• Network ID - Here, enter the number of the network ID the device resides (max. 65535).

• Port - Here, enter the UDP port for the communication to the BACnet device.

• IP-Address - Here, enter the IP address of the BACnet device.

Caution

If the same IP address or Device Id is used twice, only one connection can be established, i.e. a flawless operation can not be assured. This also applies to inactive configurations.

Commands

With the aid of these buttons specific events can be triggered on the configured device.

Time

Synchronizes the time on the device with the time of the data point element. When the zero-time is set on the data point element, the actual system time is set by the driver automatically and sent within the telegram (DM-TS-A service).

Desc

Reads-in the object descriptions from the device.

Unit

Reads-in the object units from the device.

Init

Executes a re-initialization of the device (DM-RD-A service).

GQ

Triggers a general query for the configured device. Thereby the following data can be queried at the same time:

Values/Events

Queries the object values and the events of the device.

Values

Queries the object values of the device.

Events

Queries the object events of the device.

Description

Queries the object description of the device.

Units

Queries the object units of the device.

State

In the State area information on the corresponding device are displayed. In the State text field the information on the connection state (Online/Offline) are displayed and in the failed COV text filed you get the information on the number of failed Change Of Value registrations.

In a redundant operation the status information will be returned twice: once for the active server and once for the passive server.

Restart Handling

The area "Restart Handling" allows to specify how the driver shall be have on restart. Following options are available.

Active

Activates the restart handling function

Add in recipient list

Adds the driver to the recipient list of the restart notification

Renew COV Subscription

Executes a renewal of the COV subscriptions.

Execute event GQ

Driver executes an event GQ.

Execute data GQ

Driver executes an data GQ.

Language Encoding BACnet Default 2010 / BACnet Default 2008

The WinCC OA BACnet driver in version 3.11 SP1 uses the language encoding of the BACnet standard in version 2010. Due to the fact that there occur displaying problems for texts with BACnet devices that only support the language encoding of the BACnet standard in version 2008 (or below), the language encoding can be changed for each configured device.

To use the encoding of the older BACnet standards (version 2008 or below), the fourth bit inside the internal data point element _BacnetDevice.Flags must be set to the value "1" (see the red marking in the figure below).