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The description of working mode of LoRa gateway LG220-H

The description of working mode of LoRa gateway LG220-H

2020-06-12

2020-06-12
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The description of working mode of LoRa gateway LG220-H

1. Wake up polling mode

After the LoRa gateway LG220 sets this mode, the network node module will enter the passive wake state.

The nodes are evenly distributed among the three channels after they are connected to the network:

 

Note:

Channel 1 is a channel for controlling the node and channel 2,3 and 4 is four communication.

Before the node contact with the LoRa gateway LG220 the speed and the Channel must be the same with the settings of channel 1 in LoRa gateway LG220.

The speed must same and the information channel must be different between channel 2, channel 3, and channel 4.

 

Built-in web page related time parameters:

Polling data settings(Maximum is 16):

LoRa gateway LG220 will send leading code for waking node up and polling data to each node at all the channels. The overall time frame is shown below:

 

 

Notice:

1.The polling process is carried out in three channels simultaneously.

2. After the first data has been polled for all nodes in each channel then polls the second data.

 

Wake cycle time:

Each node receive the package data in the same time and they send to the package to the serial port device to wake them up, and then they have a period time to wait for serial port to send the data back to the node, this time is called wake cycle time, default is 2000ms. The maximum time is 65533ms.

If there is no data send from the device node will enter low power mode.

 

Receive time out time:

If each node receiving the data from the serial port device they have a period time to send data back to LG220. After the node sends data to the LG220 node will enter low power mode.

This time is called receive timeout time. The maximum time is 65533ms.

When the serial port receives the polling data, the LoRa gateway LG220 will immediately issue the second data if all the node responds to the LoRa gateway LG220 immediately.

Waiting for all nodes to be polled in all the channels, then poll all the data again for each node in the next channel. The period time between the end of the first polling process and the beginning of the second polling process is called Polling interval time.

 

Specific parameter setting schedule:

Node number

Speed

Wake recycle

Polling interval

Receive timeout

Maxmium polling time

3

1.758Kbps

2000ms

1000ms

1000ms

2300.03ms

12

3.125Kbps

2000ms

1000ms

500ms

3614.04ms

30

6.250Kbps

2000ms

1000ms

500ms

3801.3ms

120

10.937Kbps

2000ms

1000ms

100ms

6807.2ms

300

21.875Kbps

2000ms

1000ms

100ms

13529ms

 

Mode application:

Wake up polling mode is used for collecting the data such as Modbus RTU protocol. After receiving the “Reading message” the sensor will give back an “answer ” to servers.

Set the LoRa gateway LG220 polling data to Modbus RTU ask frame as above picture:

Application: if you want to know each refrigerator’s temperature in the shop.you can put some sensors in the refrigerator  

 

2. Node active report mode 

Node active report mode is similar to the wake recycle mode. The node can send the data activity without asking command. But the device connects with LG206-C needs to get the correct data to be sent from the LG220.

And then the MCU in the device can send the data to LG206 and the LoRa gateway LG220.

 

Mode application:

 

The network access process is similar to wake up polling mode,please refer to the wake-up mode.

 

Correlation time parameter:

Polling data is carried out simultaneously on three channels. I'm just going to introduce one channel here.

Total delivery time = Data sending time + Time slot

Reported cycle=Total delivery time*Node amount(How many node)+Reserved slot

Data sending time:

We can calculate the time of data transmission by bandwidth, spread spectrum factor, and related parameters.

The formula is as follows:

 

And we also have the special calculator as follows:

For example: if you have 300 nodes totally, and each channel is 100. The message length is 10 bits. The speed is 7. The minimum Reported cycle for all the nodes is 133200ms(2.22min).

You can send your message length and node amount Our engineer will calculate for you.