Updated BACnet connector advanced configuration section

Author: samson0v

_includes/templates/iot-gateway/bacnet-connector/examples/time-series-and-attributes/dynamic-device-name-and-profile.md

@@ -17,3 +17,6 @@ You can use the following variables to extract specific device information:
 - "**Device ID: ${objectId} at ${address}**" If the objectId variable exists and contains **"vendorId": 999** and 
   address variable exists and contains **"address": "192.168.1.1"**, the device on platform will have the following 
   name: **Device ID: 999 at 192.168.1.1**.
+
+You can find full list of available variables in
+the [Advanced configuration](/docs/iot-gateway/config/bacnet/#available-variables-for-device-nameprofile-expressions) section.

docs/iot-gateway/config/bacnet.md

@@ -284,6 +284,17 @@ Example of the application configuration:
 }
 ```
 
+### Foreign device (v.3.7.6+)
+
+The foreign device configuration parameters are used to configure the gateway as a foreign device in the BACnet network.
+It is useful when the gateway is behind a NAT and needs to register with a BACnet Broadcast Management Device (BBMD).
+
+| **Parameter**              | **Default value** | **Description**                                   |
+|:---------------------------|-------------------|---------------------------------------------------|
+| foreignDevice.ttl (in sec) | **900**           | Time to live for the foreign device registration. |
+| foreignDevice.address      | **0.0.0.0**       | The address of the BBMD to register with.         |
+| ---                        |                   |                                                   |
+
 ### Devices
 
 The device list contains an array of BACnet devices that can be connected to the connector and interact with them. 
@@ -329,6 +340,20 @@ Example of the device mapping configuration:
 }
 ```
 
+#### Available variables for device name/profile expressions
+
+You can use the following parameters for forming device name and profile:
+- `${objectName}` - the device object name of the BACnet device.
+- `${objectId}` - the device object identifier of the BACnet device.
+- `${vendorId}` - the device vendor identifier of the BACnet device.
+- `${address}` - the device host address.
+- `${routerId}` - the device router identifier.
+- `${routerName}` - the device router name.
+- `${routerAddress}` - the device router address.
+- `${routerVendorId}` - the device router vendor identifier.
+
+You can find detail examples [here](/docs/iot-gateway/config/bacnet/#usage-examples).
+
 #### Device attributes and time series
 
 | **Parameter**                         | **Description**                                                                                                 |