CRC Generator

Category: Hash & MAC & CRC · Node Type ID: utility-crc

Universal Parametric Cyclic Redundancy Check (Rocksoft Model: 8, 16, 32, 64-bit)

Overview

Computes a non-cryptographic Cyclic Redundancy Check (CRC) checksum over a byte array using the universal Rocksoft™ Parametric CRC Model across 8-bit, 16-bit, 32-bit, or 64-bit register widths.

You can select one of 7 built-in industry presets (such as CRC-32 for Ethernet/ZIP/PNG, CRC-16/CCITT-FALSE, CRC-16/MODBUS, or CRC-64/XZ) or switch CRC Algorithm Preset to Custom to reveal five Rocksoft parameters (Width, Polynomial, Initial Value, Reflect In, Reflect Out, and XOR Out). The computed checksum is emitted as a big-endian byte array (1, 2, 4, or 8 bytes).

When to Use

Calculating frame check sequences (FCS) or packet checksums for industrial protocols (MODBUS, CAN, XMODEM), storage formats (ZIP, PNG, XZ), or smartcard APDU frames.
Prototyping custom proprietary CRC polynomials using the full Rocksoft parameter set.

Parameter Configuration

Parameter (ID)	Type & Default	Visibility Condition	Description & Options
CRC Algorithm Preset `preset`	`select` Default: `CRC-32/ISO-HDLC`	Always visible	Selects a standard CRC preset or `custom` to configure raw Rocksoft model parameters. `CRC-32/ISO-HDLC`: CRC-32 / ISO-HDLC (Ethernet/PNG/ZIP) `CRC-32/CASTAGNOLI`: CRC-32C / Castagnoli (iSCSI/Ext4) `CRC-16/MODBUS`: CRC-16 / MODBUS (Industrial) `CRC-16/CCITT-FALSE`: CRC-16 / CCITT-FALSE `CRC-16/XMODEM`: CRC-16 / XMODEM `CRC-16/USB`: CRC-16 / USB `CRC-16/ISO-14443-A`: CRC-16 / ISO 14443-A (MIFARE/NFC) `CRC-8/SMBUS`: CRC-8 / SMBUS `CRC-8/MAXIM`: CRC-8 / MAXIM (Dallas/1-Wire) `CRC-64/ECMA`: CRC-64 / ECMA-182 `CRC-64/XZ`: CRC-64 / XZ (GO-ISO) `custom`: Custom (Rocksoft Model Parameters)
Custom Width (Bits) `customWidth`	`select` Default: `32`	Always visible	CRC register width in bits (`8`, `16`, `32`, or `64`), producing a 1, 2, 4, or 8-byte big-endian output. Only visible when `Preset = custom`. `8`: 8-bit `16`: 16-bit `32`: 32-bit `64`: 64-bit
Custom Polynomial (Hex) `customPoly`	`hex` Default: `04C11DB7` Supports Variable Reference (`$var`: `bytes`)	Always visible	Generator polynomial in hexadecimal (without leading MSB 1, e.g., `04C11DB7` for CRC-32). Only visible when `Preset = custom`.
Custom Initial Value (Hex) `customInit`	`hex` Default: `FFFFFFFF` Supports Variable Reference (`$var`: `bytes`)	Always visible	Initial register fill value in hexadecimal (e.g., `FFFFFFFF`). Only visible when `Preset = custom`.
Reflect In (refIn) `customRefIn`	`boolean` Default: `true` Supports Variable Reference (`$var`: `bool`)	Always visible	When enabled (`true`), reflects each input byte LSB-first before shifting into the register. Only visible when `Preset = custom`.
Reflect Out (refOut) `customRefOut`	`boolean` Default: `true` Supports Variable Reference (`$var`: `bool`)	Always visible	When enabled (`true`), reflects the final register bit order before applying `XOR Out`. Only visible when `Preset = custom`.
Custom XOR Out (Hex) `customXorOut`	`hex` Default: `FFFFFFFF` Supports Variable Reference (`$var`: `bytes`)	Always visible	Hexadecimal mask XORed with the final register value before output (e.g., `FFFFFFFF`). Only visible when `Preset = custom`.

Port I/O Specification

See Ports & Connections for general wiring rules, data type colors, and dynamic port creation.

Input Ports

Port Nature: Fixed Input Ports (1 total).

Port Name	Port ID	Data Type	Required	Visibility Condition	Description
`Data`	`data`	`Bytes`	Required	Always visible	Input byte array (`Uint8Array`) over which to compute the CRC.

Output Ports

Port Nature: Fixed Output Ports (1 total).

Port Name	Port ID	Data Type	Visibility Condition	Description
`Checksum`	`checksum`	`Int`	Always visible	Computed CRC checksum as a big-endian byte array (1B for 8-bit, 2B for 16-bit, 4B for 32-bit, 8B for 64-bit).

Error Cases

When any of the following conditions occurs at runtime, this node transitions to an ERROR state and downstream nodes connected to its outputs do not execute.

Error Code	Default Engine Message	Trigger Condition
`INVALID_CRC_PARAMETER`	Invalid CRC custom parameter (Hex)	Raised when a custom Rocksoft CRC parameter (`Polynomial`, `Initial Value`, or `XOR Out`) is not a valid hexadecimal string.

Examples

Verifying the Standard "123456789" Check Value (0xCBF43926)

Compute the IEEE 802.3 CRC-32 of the ASCII string "123456789".

Convert "123456789" to bytes via String to Bytes and connect to Data.
Select CRC-32 (IEEE 802.3 / Ethernet / ZIP / PNG); CRC Checksum outputs the 4-byte buffer cbf43926.