LGF_CalcCRC8For1Byte (FC / 3.0.1)

Author: Siemens Industry Support

Short description

The CRC calculation is used for error detection at data transmission. The result of a calculation returns a CRC value via the data sent (Byte). The receiver detects a faulty transmission due to the unequal CRC value. The function LGF_CalcCRC8For1Byte uses 8 bits as the generator polynomial (mask).

Block Interface


Byte	initValue	Ret_Val	Byte
Byte	initValue	Ret_Val	Byte
Byte	mask
Byte	mask
Byte	value
Byte	value

Input parameter

Identifier	Data type	Description
initValue	Byte	Start value with which the calculation is executed. If there is no need for start value - assign 16#00
mask	Byte	Generator polynomial with which the calculation is executed. (Mask / CRC polynomial)
value	Byte	Data byte for which the CRC value will be calculated.

Output parameter

Identifier	Data type	Description
Ret_Val	Byte	Calculated CRC value (return value of the function).

Functional description

The function calculates the CRC value from a data byte value. The start value initValue and the generator polynomial mask can be freely selected.

Note: Various online tools are available for calculating the CRC values. The function of the block was tested with the following online tool, since it supports the input parameters mask (Polynomial) and initValue (Initial Value):; http://www.sunshine2k.de/coding/javascript/crc/crc_js.html

Change log

Version & Date		Change description
	1.0.0	Siemens Industry Online Support
	03.07.2018	First released version
	1.0.1	Siemens Industry Online Support
	17.08.2018	Upgrade: TIA V15 Update 2
	1.0.2	Siemens Industry Online Support
	23.11.2018	Upgrade: TIA V15.1
	1.0.3	Simatic Systems Support
	09.10.2019	Code refactoring, comments added
	3.0.0	Simatic Systems Support
	23.04.2020	Set version to V3.0.0, harmonize the version of the whole library
	3.0.1	Simatic Systems Support
	12.11.2020	Insert documentation Assign default start values to optional inputs - `initValue`, `mask`