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LoRaWAN COMFORT CO2 - Guide utilisateur / User guide version V1.1.1
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2.7.1 Periodic transmission with redundancy
The redundancy mechanism allows the user to add previous data in the current frame (see here under example). Thanks to this mechanism the
device keep a number of samples in its local memory to send them again in the new frame.
The associated parameters linked to this mode are:
• Sampling period (register 321), historisation frequency (register 320) and transmission frequency (register 301)
• The number of samples to be repeated in the next frame (register 323).
When redundancy is activated the frame will contain the number of bytes corresponding to the total of samples, that is S301+S323.
At the start-up of the device, the redundant signed bytes are completed by zeros until there is memorized samples.
Example with redundancy:
Register Encoding
value
Value
Result
S321
Decimal
1800
1 sample every hour
(1800 x 2 seconds = 60 minutes)
S320
Decimal
1
1 historisation at each sampling
S301
Decimal
2
1 transmission every 2 savings
S323
Decimal
4
4 redundant samples per frame
In this example:
• 1 sampling done every hour (1800x2seconds = 60 minutes)
• The historisation is made at each sampling
• The transmission is made every 2 savings (historisation) so every 2 hours
• The device will send a frame with 2 new samples and 4 memorized samples.
In this example, thanks to redundancy, if a frame is lost, the data is recovered in the 2 next frames.
New samples
Memorized samples
Time
Historisation/
Saving
Frame 1
Frame 2
Frame 3
Frame 4
Frame 5
Frame 6
Frame 7
1h 2h 3h 4h 5h 6h 7h 8h 9h 10h 11h 12h 13h 14h 15h
Transmission
