Specifications

Revision 2.4 WebRelay-Quad™ Users Manual
Character String Example:
char write_registers_mb_request =
{0x00, 0x01, 0x00, 0x00, 0x00, 0x0b, 0xff, 0x10, 0x00, 0x10, 0x00, 0x02, 0x04,
0x00, 0x00, 0x41, 0x20 };
Response
Modbus/TCP:
Transaction identifier (2 Bytes): 0x0001
Protocol identifier (2 Bytes): 0x0000
Length (2 Bytes): 0x0006
Unit identifier: 0xff
Modbus:
Function (1 Byte): 0x10 (Write Multiple Registers)
Reference number (2 Bytes): 0x0010
Word count (2 Bytes): 0x0002
Modbus Error:
Function code (1 Byte): 0x90
Exception code (1 Byte): 0x01, 0x02, 0x03, or 0x04
Exception codes:
0x01 - Function code not supported
0x02 - Incorrect starting address / quantity of outputs combination
Character String Example:
char write_registers_mb_response[] =
{0x00, 0x05, 0x00, 0x00, 0x00, 0x06, 0xff, 0x10, 0x00, 0x10, 0x00, 0x02 };
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