Enter your Modbus RTU Data along with Input Format, Output Format, Baud Rate, Data Bits, Parity, and Stop Bits to calculate the CRC-16 Checksum and get the full Complete RTU Frame, Frame Length, Transmission Time, and Character Interval for your serial configuration.
CRC-16 Checksum
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Complete RTU Frame
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Frame Length
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Transmission Time
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Character Interval
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Frame Interval
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Modbus RTU uses CRC-16 (Cyclical Redundancy Check) for error detection. It's a 2-byte checksum calculated from all bytes in the frame except the CRC itself, helping ensure data integrity during transmission.
The CRC-16 uses polynomial 0xA001 (reversed 0x8005). The calculation starts with 0xFFFF, processes each data byte, and the final result is appended as low byte first, then high byte.
Modbus RTU requires a silent interval of at least 3.5 character times between frames. For baud rates ≤19200, use exact 3.5 character calculation. For higher rates, use minimum 1.75ms.
Character interval is the time between individual bytes (1.5 character times max), while frame interval is the silent time between complete frames (3.5 character times minimum).
Enter hex bytes separated by spaces (e.g., '01 03 00 00 00 0A'). Don't include the CRC bytes as they will be calculated automatically.
Higher baud rates reduce transmission time but require more precise timing. Rates above 19200 bps use fixed minimum intervals instead of character-time calculations.
Yes, the calculator supports various combinations of data bits (7/8), parity (none/even/odd), and stop bits (1/2) to match your specific Modbus configuration.