Keep Alive Frame; Reply Frame To A Register Value Request In A Downlink Frame; Periodic Data Frame - ADEUNIS LoRaWAN MODBUS MASTER Guide Utilisateur

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

4.1.4 Keep Alive frame

This frame (0x30) is transmitted only in the event mode at the frequency defined by register 300.
0 1
Code Status
0x30 Cf Status
FR
0x30 0xB3
Its size is of 2 bytes.
It contains only the code byte (0x30) and the status byte.

4.1.5 Reply frame to a register value request in a downlink frame

EN
Following reception of a downlink frame with the code 0x40, the frame 0x31 is transmitted.
It contains all the values of the registers requested in the downlinl frame 0x40.
Example :
• Frame (0x40) sent to the product (downlink):
0 1
Code Status
0x40 CONFID1
The CONFIDX (8bits) fields represent the indices of the registers to be sent. The corresponding register is 300 + CONFIDX value.
• Response frame (0x31) from the product:
0 1
Code PAYLOAD
0x31 Status
In this example: CONFID1 is a 2-byte register, CONFID2 a 1-byte register and CONFID3 a 2-byte register.
If an error is detected in the request, the returned 0x31 frame will be empty.

4.1.6 Periodic data frame

This frame (0x44) is transmitted at the frequency defined in register S301 and contains all the configured Modbus periodic data.
The organization of the bytes in this frame therefore depends on the configuration of the user by following the scheduling of the defined
MODBUS frames.
This frame has a maximum of 24 2-byte registers.
0 1
Code Status
0x44 Cf Status
Its size is of 50 bytes.
2 3 4
CONFID2 CONFID3 X
2 3
VALUE1 VALUE1 VALUE2
2 to 3 4 to 5
Modbus Modbus
Register 1 Register 2
5 ...
PAYLOAD
X X
4 5 ...
PAYLOAD
VALUE3 VALUE3
6 to 7 8 to 9
PAYLOAD
Modbus Modbus
Register 3 Register 4
7
CONFID8
11
X
... 48 to 49
... Modbus Regis-
ter 24
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