This article is a tutorial for users who configured a Modbus IP Gateway into their HUB/BOX, which is redirecting Lorawan sensors values. You can learn more about setting up a Modbus IP Gateway from this tutorial.
Downlink specifications are explained in sensor manufacturer documentation only.
Be sure that you configured a Modbus IP Gateway redirecting the correct properties. In order to send a downlink, the property "Encoded downlink message" is required.
Remember the address of the property. Here is 268.
The type of the property is Text and should not be changed.
Go to your Modbus client interface and connect to your Wattsense device IP address. You should be able to find it on the Configuration > Connectors tab.
For this example, I am using my computer as my Modbus client, using the software ModbusDoctor.
- Set the address of the Encoded downlink message property. (268 in my example)
- Set the type as Holding register.
- Configure the number of registers of the downlink, depending on its size. (A single register contains 16 bits, so you can put 2 ASCII characters per register).
- In this exemple, we send the following downlink: 401E20:1
(This downlink contains 8 characters so we can set the size to 4)
- Write 2 ASCII characters of your downlink in each register area.
- Click on WRITING to send the downlink.
Be aware that for a Class A Lorawan sensor, the downlink will be received only right after it sends an uplink. If you send multiple downlinks they will be stored and sent to the sensor one by one. Link to further documentation about Lorawan downlink.