Advanced Features

Send Downlinks using the Queue

This section shows you how to use the network server to send downlinks to the device.

Prerequisites

You can construct downlinks in HEX, Base64, or JSON format. To use the JSON format, you first need to have created a device profile with a payload codec defined that includes an encode downlink function (encodeDownlink(input)). The encode downlink function instructs Semtech Network Server how to convert the JSON into a byte array.

If you did not add your device using the device profile template feature, and it is an off-the-shelf device, open Device Profiles in the left hand menu, choose the device profile, click the Select device-profile template button, and search for your device. If found, the device profile will be updated and may include a codec.

Before sending your downlinks, locate the user manual for your device. This should contain additional detail about the values that can be submitted to the end device.

If there is no codec for your device, or you built your own device, learn how to construct the encode downlink function on the ChirpStack documentation Device profiles page.

You will also need at least one device using the device profile joined to the network if it uses over-the-air activation (OTAA), or turned on if it uses activation-by-personalization (ABP).

Adding Downlinks to the Queue using JSON

1. Log in to the Semtech Network Server website if you haven’t already done so.

2. Click Applications in the menu on the left.

3. Click the link to the application containing the device you want to inspect.

4. The devices registered to the application appear. Click the link in the DevEUI field of the device you wish to send a message to.

5. Select the Queue tab. The Enqueue form appears.

6. Consult the user manual to find the available options for downlinks that can be sent to your device. These typically include changing device settings such as configuring how often the device reports data.

   Review the encode downlink function and compare with the user manual to work out how to construct the downlink. Here is an example of a JSON object, with two fields for an imaginary device that allows you to modify how frequently an uplink is sent.

   {
   "MinTime": 600,
   "MaxTime": 900
   }
   

   We refer to this code block as DOWNLINK_JSON.

7. Check the Confirmed box if you want the downlink to be sent as a confirmed downlink, requiring the end device to send an acknowledgement when it has received it.

8. Consult the user manual to identify the Frame Port with which the message should be sent and enter that value into the FPort field.

9. Select the JSON tab in the Enqueue form and paste in the DOWNLINK_JSON code block you just created, replacing the existing code.

   

10. Click the Enqueue button to add the downlink to the queue.

11. The downlink appears in the queue, as shown in Figure 2.

    

    When the end device next sends a Class A uplink, the downlink will be sent to the end device in the receive windows.

Configure Measurements and View Device Metrics in the Dashboard

This section shows you how to build your own dashboard for each device directly in the Semtech Network Server.

You must have a device profile with a payload codec defined, and at least one device using that profile, to proceed.

Register Device Measurements

1. Log in to the Semtech Network Server website if you haven’t already done so.

2. A dashboard is generated per device; the settings for the dashboard are defined per device profile. Click Device profiles in the menu on the left, and then click on the name of the device profile you want to create a dashboard for.

3. If you haven’t already, join at least one device that uses this device profile to the network. Wait for each type of uplink supported by the device to be received by the network server as explained in Join the Network and View Events and LoRaWAN® Frames. If you aren’t sure how long to wait, perform the action that causes the device to trigger, and then wait for 24 hours.

   Note

   After the network server has received an uplink using the device profile codec, it sets the field keys in the device profile Measurements tab with every field decoded in the codec. If you do not wait for the network server to decode the uplinks and populate the field keys, you must enter the Measurements keys yourself after inspecting the codec.

4. Click Device profiles in the menu on the left.

5. Click on the Device profile for the device model and firmware version for which you want to view data.

6. Click on the Measurements tab.

7. You see a row for each field identified by the auto-detect feature displays, with three columns, as shown in Figure 3.

   

   The left hand column, marked A in Figure 3, contains the measurement key name. This key name matches one of the fields returned by the decodeUplink(input) function in the device profile codec, which you can view by clicking on the Codec tab and scrolling down inside the Codec functions field to the decodeUplink(input) function. In this function, a data object has keys attached. The names of these keys are the same as the names of the keys in the list in the Measurements tab.

   At the next column, marked B in Figure 3, you set the measurement type. For each measurement key, you must inspect both the codec and the user guide for your device model and firmware version and set the dropdown to the measurement type in the following list that most closely matches the measurement.

   • Unknown / unset:

     This is the default for all keys. If you leave the measurement type set to this, you will not see any data for this measurement. Even if you aren’t sure which type to choose, you should try one of the other options if you want to view the data on the dashboard.

   • Counter:

     Choose the Counter option if this measurement is a number which increments, and never decreases. For example, Counter could be used for a device measurement that counts the number of times motion has been detected, returning 1 the first time it is triggered, 2 the next and so on.

   • Absolute:

     Choose the Absolute option if this measurement is a counter which is reset to zero when each uplink is broadcast.

   • Gauge:

     Choose the Gauge option if this measurement is a reading with a minimum and maximum level. For example, use Gauge for battery voltage, temperature, and humidity.

     

   • String:

     Choose the String option if this measurement is returned from the codec as a string value or is an on/off boolean value. For example, a low battery warning that returns text such as ‘low battery’; a leak detector that returns a 1 or a 0 depending on whether a leak is detected or not.

     Figure 5 shows the dashboard widget that appears when the String option is selected.

     

   At the last column, Measurement Name, marked C in Figure 3, enter a label for the dashboard widget that displays the data for this measurement. You must enter a Measurement Name value for every measurement you wish to have visible on the dashboard.

8. If there are any measurements you do not wish to appear on the dashboard, set the measurement kind to Unknown / unset.

9. Click the Submit button to save the measurements.

View the Device Dashboard

1. Click Applications in the menu on the left.

2. Click on the link to the application containing the device you want to inspect.

3. The devices registered to the application appear. Click on the link in the DevEUI field of the device you wish to inspect.

4. Click on the Device metrics tab inside the open Dashboard tab, as shown in Figure 6.

   

5. A widget appears for each measurement you configured.

Viewing LoRaWAN® Messages

This section explains the different ways you can view messages received from and sent to the network server, either per device or per gateway. These messages can be used for debugging purposes.

View Device Frames

The device LoRaWAN frames tab lets you view messages received by the network server from the selected device as well as all messages sent to the device by the network server.

1. Log in to the Semtech Network Server website if you haven’t already done so.

2. Click Applications in the menu on the left.

3. Click the link to the application containing the device you want to inspect.

4. The devices registered to the application appear. Click the link in the DevEUI field of the device you wish to inspect.

5. Select the LoRaWAN frames tab.

6. View the details of any frame by clicking the magnifying glass icon ( ) in the frame to open the Details pane for that specific frame.

   Warning

   If the network server is unable to authenticate the device, the messages sent from the device will not be displayed in the device LoRaWAN frames tab. All messages, even those failing authentication, can be seen in the gateway frames described below in the section View Gateway Frames.

   If you do not find messages in the device LoRaWAN frames tab, check the gateway LoRaWAN frames tab to see if the messages are being received by the gateway. You can then determine whether the network server receives and then rejects messages from this device, or if the network server does not receive messages from this device.

Each frame includes the following fields, indicated in Figure 7:

• Timestamp (indicated at A in Figure 7) - this indicates when the frame was received or sent by the network server.

• Label (at B) - the label indicates the type of frame. Labels include:

  • JoinRequest - Frame sent from the device to the network server to initiate the join process. Learn more about the Join Request frame.

  • JoinAccept - Frame sent from the network server to the device to confirm the join process is completed. Learn more about the Join Accept frame.

  • UnconfirmedDataUp - Frame sent from the device to the network server that do not require a response. Learn more about uplink frames.

  • ConfirmedDataUp - Frame sent from the device to the network server that requires a response from the network server. Learn more about uplink frames.

  • UnconfirmedDataDown - Frame sent to the device from the network server that do not require a response. Learn more about downlink frames.

  • ConfirmedDataDown - Frame sent to the device from the network server that requires a response from the device. Learn more about downlink frames.

  Note

  Data frames (ConfirmedDataUp, UnconfirmedDataUp, ConfirmedDataDown, UnconfirmedDataDown) may contain application data, MAC commands, or both. A message may also carry no application data nor MAC commands. Learn more about different types of data carried in data frames.

• DevAddr (at C) - the device address allocated by the network server.

• DevEUI (at D) - the device EUI, provisioned on the device.

• Gateway ID (at E) - the ID of the gateway used to send this frame.

  Note

  Only frames sent from the network to a device (JoinAccept, ConfirmedDataDown, and UnconfirmedDataDown) have a Gateway ID. This is because frames sent from a device to the network server are sent using all gateways in the vicinity connected to this network server. Frames sent from the network server to the device are sent using the gateway the network server has identified as the most suitable gateway to broadcast from. The Gateway ID identifies this gateway.

Create an Application Integration

This section shows you how to configure an HTTP application integration so you can view your device data outside the Semtech Network Server. You can also use the integrations feature to connect your devices to major cloud platforms including AWS, Azure, and Google Cloud, as well as IoT platforms such as ThingsBoard and IFTTT.

The free service Hookbin allows you to quickly create a POST endpoint for use with the HTTP integration. Other services are available such as RequestBin, or you can create your own service. We supply instructions for Hookbin, but you can choose to use an alternative service if you prefer.

Add Additional Users

Semtech Network Server allows you to add multiple team members with different user rights.

1. Log in to the Semtech Network Server website if you haven’t already done so.

2. Click Users in the menu on the left.

3. Click the Add tenant user button to add another user.

4. Complete the Add tenant user form as follows:

   • Email (of existing user):

     Enter the email address of an existing Semech Network Server user to add to this tenant.

   • User is tenant admin:

     Switch this on to allow the user to perform all tasks, including managing applications, device profiles, devices, gateways, and users. Tenant admin is a super user, so all additional options disappear if selected.

   • User is gateway admin:

     Switch this on to allow the user to create, edit, and delete gateways in this tenant.

   • User is device admin:

     Switch this on to allow the user to create, edit, and delete devices, device profiles, and applications.

   Note

   If you do not turn any switches on, the user can see all data, but will not be permitted to make modifications.

5. Click the Submit button to add the new user.

When this user signs in, their own tenant is selected. They must select your tenant from the dropdown at the side of the left menu after signing into the network server, as shown in Figure 10.