Downlink Frames - ADEUNIS sigfox MODBUS MASTER Guide Utilisateur

sigfox MODBUS MASTER - Guide utilisateur / User guide version V1.0.0

4.2. Downlink frames

SIGFOX technology allows up to 4 downlink messages to be transmitted (from the network to the product) per day depending on the subscrip-
tion.
A downlink message is in fact an acknowledgement of receipt of an uplink frame with a request for acknowledgement. This means that, to
receive a message on the product, an uplink frame (from the product to the network) must indicate an acknowledgement wait.
FR
This acknowledgement downlink frame is an 8 byte message defined for the adeunis® product in the following two paragraphs.
Hence the product sends an uplink frame with the ACK field enabled, it then returns to standby for twenty seconds before opening a reception
window (RX window) for a maximum of 30 seconds, in accordance with the diagram below:
EN
The configuration of the sending policy of the acknowledgement request in the adeunis® product differs according to whether the product is in
periodic or event mode:
• In periodic mode: the transmission period for the event counters (register 301) allows us to know the number of uplink frames that the
product will send per day. This number is divided by the number of downlink frames per day (register 307) and allows us to set the schedule of
acknowledgement requests so that the network can transmit its downlink frames.
• In the event mode: the only known periodicity is that of the Keep Alive frame, defined by register 300, because it is possible that no event
occurs in 24 hours. The acknowledgement requests and hence the possibilities for the network to transmit this data are determined by the perio-
dicity of the Keep Alive frame (register 300).
E.g.:
• The product is running in the periodic mode
• S301 = 180 i.e. a periodicity of sending of frames of 60min, every hour or 24 times per day.
• S307 = 4, we wish to perform 4 downlink frames per day
Result: The value of S301 gives us 24 frames per day that are divided by the value of S307 to obtain the result of 6. Thus for all 6 Periodic
frames the acknowledgement request will be transmitted thus enabling the network to send a downlink frame.
• The product is running in the event mode
• S300 = 36 i.e. a periodicity of sending of frames of 360min, i.e. Every 6 hours or 4 times per day.
• Result: the acknowledgement request will be transmitted 4 times per day thus enabling the network to send a downlink frame.
Caution: The configuration of the downlink frames has impacts on consumption and therefore on the life of the product since it must then open
listening windows and no longer be in standby. On the other hand, as the SIGFOX network limits to 4 the number of downlink frames if the
product configuration allows us to do a lot more, there will be no more response from the network and the acknowledgement that the product
is waiting for will not come.
Page 66 of 80