CRC-16/MODBUS Checksum
Calculate CRC-16/MODBUS over UTF-8 text with polynomial 0x8005, initial value 0xFFFF, and final XOR 0x0000.
Description
Calculate CRC-16/MODBUS Checksum over UTF-8 text and display the result as uppercase hexadecimal.
CRC-16/MODBUS Checksum is intended for interoperability and accidental-error detection. CRC-16/MODBUS uses a 16-bit register, polynomial 0x8005, initial value 0xFFFF, final XOR 0x0000, and reflected byte processing.1
When to use CRC-16/MODBUS Checksum
Use this checksum only when a file format, device, protocol, or published test vector specifies the same named profile and parameters. Profiles with the same width can still produce unrelated results.
How CRC-16/MODBUS Checksum works
CRC-16/MODBUS uses a 16-bit register, polynomial 0x8005, initial value 0xFFFF, final XOR 0x0000, and reflected byte processing.1
How the CRC-16/MODBUS function processes input
- Encode the entered text as UTF-8 bytes.
- Process the bytes with the selected algorithm and its exact parameters.
- Render the result in the canonical textual form shown by the tool.
Limitations and assumptions
- Checksums are not collision-resistant and must not be used as digital signatures or security proofs.
- Text is encoded as UTF-8; a checksum over a file's raw bytes can differ.
- Every CRC parameter—including reflection and initialization—must match the other implementation.
Alternative or Complementary approaches
Use a cryptographic hash such as SHA-256 when malicious modification is in scope. Use the custom CRC calculator when a documented profile is not available as a preset.
References
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Catalogue of parametrised CRC algorithms — CRC RevEng
Similar or alternative tools
- CRC-32 Checksum
Use the common ISO-HDLC CRC-32 profile.
- SHA-256 Hash Generator
Use a cryptographic digest for adversarial integrity.