Modbus over serial, RTU transmission mode. Frame boundaries are marked by line silence rather than sync bytes or a length field.
Physical UART Transport (115200 bps, 8N1.0)
Send command ReadCoilsRequest (ID: 0x01)
Function 0x01: Read boolean coils status.
Available only on servers:
Accepts the following message:
Function 0x01: Read boolean coils status.
{
"command_id": 1,
"slaveAddress": 0,
"startAddress": 0,
"quantity": 0
}
Send command ReadDiscreteInputsRequest (ID: 0x02)
Function 0x02: Read discrete inputs status.
Available only on servers:
Accepts the following message:
Function 0x02: Read discrete inputs status.
{
"command_id": 2,
"slaveAddress": 0,
"startAddress": 0,
"quantity": 0
}
Send command ReadHoldingRegistersRequest (ID: 0x03)
Function 0x03: Read a block of holding registers.
Available only on servers:
Accepts the following message:
Function 0x03: Read a block of holding registers.
{
"command_id": 3,
"slaveAddress": 0,
"startAddress": 0,
"quantity": 0
}
Send command ReadInputRegistersRequest (ID: 0x04)
Function 0x04: Read a block of input registers.
Available only on servers:
Accepts the following message:
Function 0x04: Read a block of input registers.
{
"command_id": 4,
"slaveAddress": 0,
"startAddress": 0,
"quantity": 0
}
Send command WriteSingleRegisterRequest (ID: 0x06)
Function 0x06: Write one holding register.
Available only on servers:
Accepts the following message:
Function 0x06: Write one holding register.
{
"command_id": 6,
"slaveAddress": 0,
"registerAddress": 0,
"value": 0
}
Send command WriteMultipleRegistersRequest (ID: 0x10)
Function 0x10: Write multiple holding registers.
Available only on servers:
Accepts the following message:
Function 0x10: Write multiple holding registers.
{
"command_id": 16,
"slaveAddress": 0,
"startAddress": 0,
"quantity": 0,
"byteCount": 0
}
Function 0x01: Read boolean coils status.
Function 0x02: Read discrete inputs status.
Function 0x03: Read a block of holding registers.
Function 0x04: Read a block of input registers.
Function 0x06: Write one holding register.
Function 0x10: Write multiple holding registers.