here is modbus firmware for HAv2.
Modubs command-05 (control digital output):
turn ON output1:
send:0A 05 00 00 FF 00 8D 41
feedback:0A 05 00 00 FF 00 8D 41
turn OFF output1:
send:0A 05 00 00 00 00 CC B1
feedback:0A 05 00 00 00 00 CC B1
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Modubs command-01 (read digital output state):
send:0A 01 00 00 00 06 BD 73
feedback:0A 01 01 01 92 6C (output1=ON, output2--6=OFF)
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Modubs command-02 (read digital input state):
send:0A 02 00 00 00 06 F9 73
feedback:0A 02 01 01 62 6C (input1=ON, input2--6=OFF)
------------------------------------
Modubs command-03 (read multi registers):
register: address: (200)dec (C8)hex digital input+digital output state
send:0A 03 00 C8 00 02 44 8E
feedback:0A 03 04 00 01 00 00 11 33
note:00 01 00 00 = 00 01 (input1=ON, input2--6=OFF) 00 00 (output1--6=OFF)
Modubs command-05 (control digital output):
turn ON output1:
send:0A 05 00 00 FF 00 8D 41
feedback:0A 05 00 00 FF 00 8D 41
turn OFF output1:
send:0A 05 00 00 00 00 CC B1
feedback:0A 05 00 00 00 00 CC B1
------------------------------------
Modubs command-01 (read digital output state):
send:0A 01 00 00 00 06 BD 73
feedback:0A 01 01 01 92 6C (output1=ON, output2--6=OFF)
------------------------------------
Modubs command-02 (read digital input state):
send:0A 02 00 00 00 06 F9 73
feedback:0A 02 01 01 62 6C (input1=ON, input2--6=OFF)
------------------------------------
Modubs command-03 (read multi registers):
register: address: (200)dec (C8)hex digital input+digital output state
send:0A 03 00 C8 00 02 44 8E
feedback:0A 03 04 00 01 00 00 11 33
note:00 01 00 00 = 00 01 (input1=ON, input2--6=OFF) 00 00 (output1--6=OFF)