How to choose a data collector from RS485 to LoRaWAN?

This article introduces some inherent defects of common RS485-to-LoRaWAN data collectors and introduces which elements need to be focused on when selecting RS485-to-LoRaWAN data collectors.
1. Some inherent defects of ordinary RS485 to LoRaWAN data collectors
1. Some devices have a large amount of data, which exceeds the byte limit of the LoRaWAN protocol
Although, in industrial application scenarios, using RS485 to LoRaWAN can bring a series of benefits, such as wide coverage of LoRaWAN gateways, simple networking, low power consumption, and low power consumption. However, in practical applications, some special industrial application scenarios It is not possible to directly apply the RS485 to the LoRaWAN data collector.
For example, some industrial sensors do not consider the need for wireless data transmission, and the amount of data will be relatively large. For example, in some application scenarios such as vibration sensors or radar detection, the data that the sensor needs to transmit often reaches 1K bytes, and the LoRaWAN protocol can transmit The data in only 51 bytes. Therefore, in the above-mentioned special industrial application scenarios, the ordinary RS485 to LoRaWAN data collector cannot discard the data because the data exceeds the limit, making this type of sensor unable to use Lora technology to transmit data.
2. The sensor needs more control commands, which will lead to network congestion and insufficient bandwidth
Sensors in most industrial application scenarios, such as industrial site temperature sensors, need to upload data periodically in a few seconds.
If the 485 to LoRaWAN transmission method of the ordinary transparent transmission method is used, then the LoRaWAN gateway needs to issue instructions to the data collector first, and then the data collector sends instructions to the sensor, and then the sensor receives the query instruction, and then Upload sensor data. It can be seen that in the whole process, every time the sensor data needs to be uploaded, it must occupy a lot of downlink bandwidth to issue instructions. In the LoRaWAN network, there is only one downlink channel (8 uplink channels), and too many downlinks report Files will cause network congestion, and data cannot be transmitted normally.
3. The device cannot be managed remotely, configuration parameters
In actual industrial applications, devices are usually installed in restricted areas, and local configuration and maintenance cannot be conveniently performed. Therefore, remote device management capabilities are required.
For example, if you want to change the collection frequency of a certain sensor, if you cannot configure the device remotely, you need to apply to the industrial site to modify the command of a certain terminal device through the configuration line without affecting production.
But for terminals that support remote configuration, configuration commands can be sent to the device through the LoRa network, without the need for maintenance personnel to go to the site and interrupt production.
Moreover, after supporting remote configuration management, not only can the configuration of multiple devices be modified at the same time, but also the configuration can be modified periodically according to production needs, all of which can be done automatically by connecting with the background server.
2. When selecting a data collector from RS485 to LoRaWAN, several factors need to be considered
In order to ensure that the purchased RS485-to-LoRaWAN data collector can meet the needs of actual industrial application scenarios, and avoid problems that cannot be used or are not easy to use after purchase, we need to do our homework before purchasing. UART-модуль
The elements that need to be investigated before purchasing include the following aspects.
1. Is there a function of data subcontracting?
The advantage of subcontracting is that it does not need to be limited by the packet length stipulated by the lorawan protocol, and can connect some devices with relatively large data volumes. In this way, we can get rid of the 51-byte limit of the LoRawWAN protocol.
However, it should be noted that in a specific application, it is necessary to know the amount of data that the sensor needs to transmit each time, and compare it with the maximum amount of data that can be transmitted after data packetization. Therefore, after data subcontracting is adopted, the amount of data that can be transmitted is not unlimited. For example, the RS485 to LoRaWAN data collector RAK7421 of Rikewireless, the maximum amount of data for a single sensor is 1024 bytes, although compared to The 51 bytes that can be transmitted by traditional technology is already a great improvement, but it is still limited, not unlimited.
2. Is there a function of storing instructions and sending instructions or polling at regular intervals?
The function of storing instructions needs to be combined with, for example, timing functions to achieve the purpose of sending instructions to sensors at regular intervals, or polling sensors to upload data at regular intervals.
For example, when the LoRaWAN gateway does not issue instructions, the data collector RAK7421 can also issue instructions to the sensor regularly, and can also poll, so that the sensor can still upload data regularly. Thus, the number of instructions issued by the LoRaWAN gateway can be reduced, bandwidth can be saved, and network congestion can be solved.
RAK7421 can automatically synchronize the network time. After setting the timing task, it can execute related commands regularly at the specified time, query sensors or operate control switches, etc.
3. Is there a function of remotely sending Modbus commands and remotely configuring parameters?
The RAK7421 RS485-to-LoRaWAN data collector has the ability to remotely issue Modbus commands and remotely configure terminal equipment. It can realize remote unified scheduling and management of equipment through docking with the user control platform, which is convenient for the maintenance and management of sensor networks and reduces on-site configuration. workload. It is also possible to use this remote configuration capability to edit and customize the control process according to the user's business logic to realize a customized solution.
epilogue
When selecting the RS485 to LoRaWAN data collector, you need to focus on several elements, such as whether it has the function of data packetization, whether it has the function of sending commands regularly, whether it has the function of remotely sending Modbus commands, and remote configuration parameters. Only in this way can we choose a data collector that is really suitable for specific industrial application requirements, and enjoy the convenience of networking from RS485 to LoRaWAN.