The AirSLC and/or the ACR-SLC module is designed for the remote street lamp control and its diagnostic. The diagnostic is done via the broadcast DALI request to the ballast and the response from the ballast is being processed and sent via the LoRaWAN network.
The node has the LoRaWAN 1.0.3 implemented with some extra features that are suggested in the LoRaWAN stack 1.1.x. The node works with the OTAA – Over The Air Activation method where the AppEUI is set as the „zeroes“.
If the network server loses the security context, the device does rejoin in these cases:
Once every X messages there is a confirmed message being sent. If the confirmation from the network server is not provided, the device sends the confirmed message again. In total 3 messages are being sent. If none of them is confirmed, the device does rejoin.
The device does rejoin every X messages
If the security context is lost, it is possible to send rejoin via the multicast message – port 141. This works only if the node is assigned to the multicast group.
By sending a unicast or multicast message as specified in the payload description – port 1 or 51. Fail-safe and configuration
The node and its functionality are dependants on the LoRaWAN network. However, if the communication is lost, the node goes into the automatic mode where it is being controlled via the ambient light sensor. This can be configured via port 5 or port 150. This function works based on the Downlink messages.
Manual timeout – this is a value being set in minutes that defines, how long the node must be without any Downlink message before the node switches either to automatic mode or to the set value of light intensity. So for example, if the value is set for 30 minutes, there must be Downlink being sent every 30 minutes or less. If the node doesn’t receive a Downlink after 30 minutes, it switches to the automatic mode.
Manual timeout value – The value of the light intensity which is being sent if Manual Timeout is active.
Manual timeout status – Set this to the „Automatic“ in case you need the light to be controlled by the ambient light sensor, or set it to the „Manual timeout value“ if you need the lamp to stay on or off if the Manual Timeout is active
A configuration message that allows you to set all of the parameters by one message. This method of configuration is preferred. The alternative is the configuration on port 5.
The periodic Uplink message is being sent every X minutes. It can be also requested by sending 1 byte to port 2.
If the light intensity changes, the asynchronous message is being sent with the actual light intensity value.
In various installations, we have encountered 2 types of ballast. The first one which does not have the DALI bus-powered and the second one, which does. By default, the AirSLC module does not power the DALI bus and it is designed to be powered via the ballast. In case the ballast doesn’t power the DALI bus, the AirSLC module can do so by sending the „0x01“ command to port 190. By sending 0x00, the node will NOT power the DALI bus.
Let’s say we have a street that we want to control. The requirement is, that if the LoRaWAN network is offline, the lamps will detect it and start autonomous mode in less than 1 hour.
The first step would be sending the configuration to each node. Preferably to port 150, where we can also set up the multicast address. The main parameters would be:
Function: Manual – we want to control the lights by LoRaWAN messages
Manual Timeout - „60“ – 0x3C – after 60 minutes of no Downlink message, the node starts control autonomously.
Manual Timeout Value – 0x01 – Autonomous control based on the light intensity sensor
Also, the Downlink message needs to be sent every < 60 minutes. We suggest sending the Downlink every 1/3 of the time being set in „Manual Timeout“. In this case, every 20 minutes (60/3 = 20).
This can be happening because of 2 reasons:
The node is in function “Automatic”, which doesn't respond to the light control messages on port 1. The solution is to configure the node to the function “Manual”.
The DALI bus is not powered by the ballast nor by the module. The easiest check is by voltmeter and measuring the voltage between the DALI clamps on the ballast. By default, the node does not power the DALI bus. If you measure the 0 voltage on the DALI clamps, the DALI power feature on the node needs to be turned on. You can do so by sending “0x01” to port 190.
The AppEUI is by default 00 00 00 00 00 00 00 00
The multicast address is being set by sending the NwksKey and AppsKey within the configuration message on port 150. Let's say the NwksKey is: 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 and the AppsKey is: 22 22 22 22 22 22 22 22 22 22 22 22 22 22 22 22. The part where NwksKey and AppsKey are would look like: 11 22 11 22 11 22 11 22 …
The keys are not being sent together but per bytes. It is the first byte of NwksKey followed by the first byte of AppsKey. Then it is the second byte of NwksKey followed by the second byte of AppsKey and so on …
Please make sure, that when sending the multicast message, you dim the light by sending command to the port 51. The port 1 is only for unicast.