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RS485 to LoRaWAN Converter User Manual 17 / 29
Type Code 0xA8
0xA8 downlink command can be used to control the RS485 devices via LoRaWAN.
For example,
The RS485 Alarm we use here use Modbus RTU to communicate.
 The command to active alarm is: 0A 05 00 04 00 01 4C B0. Where 0A 05 00 04 00 01 is the
Modbus command to read the register 00 40 where stored the DI status. The 4C B0 is the
CRC-16/MODBUS which calculate manually.
 The command to deactivate alarm is: 0A 05 00 04 00 00 8D 70. Where 0A 05 00 04 00 00 is
the Modbus command to read the register 00 40 where stored the DI status. The 8D 70 is
the CRC-16/MODBUS which calculate manually.
So if user want to use downlink command to control to RS485 Alarm, he can use:
A8 01 0A 05 00 04 00 01 : to activate the RS485 Alarm
A8 01 0A 05 00 04 00 00: to deactivate the RS485 Alarm
A8 is type code and 01 means add CRC-16/MODBUS at the end.
3.6 Buttons
Button
Feature
ACT
If RS485 joined in network, press this button for more than 1 second,
RS485 will upload a packet, and the SYS LED will give a Blue blink
RST
Reboot RS485
PRO
Use for upload image, see How to Update Image
3.7 LEDs
LEDs
Feature
PWR
Always on if there is power
SYS
After device is powered on, the SYS will fast blink in GREEN for 5
times, means RS485-LN start to join LoRaWAN network. If join
success, SYS will be on GREEN for 5 seconds. SYS will blink Blue on
every upload and blink Green once receive a downlink message.