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Modbus CRC Calculator

Calculate, append and verify CRC-16/Modbus values for RTU request and response frames.

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CRC-16/Modbus

Enter a Modbus RTU frame

Polynomial 0xA001 · Initial value 0xFFFF

Frame bytes in hexadecimal Enter payload bytes and select Calculate CRC. The calculator appends the CRC and verifies the generated frame automatically. To check a received frame, paste the complete frame including its final two CRC bytes and select Verify entered frame.

Calculated CRC

0xCDC5

Low byte first: C5 CD
Low byte: 0xC5
High byte: 0xCD

Frame with CRC appended01 03 00 00 00 0A C5 CD

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