YO Modbus
User guide
v2.1
page 9/33
Queries and polls
YO Modbus can request up to 150 different queries from slave devices. Establishing communication
requires advance knowledge of the device’s starting registers, slave address and function codes. This
device supports the following read functions:
●
01 (0x01) Read coils
●
02 (0x02) Read discrete inputs
●
03 (0x03) Read holding registers
●
04 (0x04) Read input registers
The query data are read by Modbus RTU and sent by LoRaWAN. Each LoRa packet contains data
from the read registers. One LoRa packet can contain 5 five user-created polls, each up to 4 bytes.
NOTE
More information about queries and polls can be found in the device configuration
section.
Figure 4
Measurements from register 0x1000.
Figure 5
Measurements from register 0x106e.
