Flachmann und Heggelbacher Docklight V2.2, Руководство пользователя

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Docklight V2.2 User Manual 07/2016 Copyright 2016 Flachmann und Heggelbacher GbR
Reference
CRC-32 32 bit CRC as used in PKZip, AUTODIN II, Ethernet, FDDI.
Same as:
CRC:32,04C11DB7,FFFFFFFF,FFFFFFFF,Yes,Yes
-MOD256 Similar to MOD256, but returns the negative 8 bit result, so
the sum of all bytes including the checksum is zero.
CRC: width , polynomial ,
init ,
finalXOR , reflectedInput ,
reflectedOutput
Generic CRC calculator, where all CRC parameters can be
set individually:
width : The CRC width from 1..32.
polynomial : HEX value. The truncated CRC polynomial.
init : HEX value. The initial remainder to start off the
calculation.
finalXor : HEX value. Apply an XOR operation on the
resulting remainder before returning it to the user.
reflectedInput : Yes = Reflect the data bytes (MSB
becomes LSB), before feeding them into the algorithm.
reflectedOutput : Yes = Reflect the result after completing
the algorithm. This takes places before the final XOR
operation.
Remarks
Each of the predefined CRC algorithms (CRC-8, CRC-CCITT, ...) can be replaced by a
specification string for the generic CRC computation (CRC:8,07,00...) as described
above. We have carefully tested and cross-checked our implementations against
common literature and resources as listed in the
CRC Glossary .
Unfortunately there are a lot of CRC variations and algorithms around, and choosing (not
to mention: understanding) the right CRC flavor can be a rather difficult job. A good way
to make sure your CRC calculation makes sense is to run it over an ASCII test string of
"123456789". This is the most commonly used testing string, and many specifications
will refer to this string and provide you the correct checksum the CRC should return
when applied on this string.
Checksums in Edit Send Sequence / Edit Receive Sequence
In the Checksum tab, choose one of the predefined definition strings from the drop-down
list, or type in your own definition in the following format:
[ ( startPos , len ) ] checksumSpec [A or L] [@ targetPos ] [ # optional user comment ]
with anything inside [ ] being an optional part.
Part Description
checksumSpec Required. String that specifies the checksum algorithm and its
parameters, according to the
checksumSpec Format table above.
( startPos , len )
e.g.
(1, 4)
Optional. Start and length of the character area that is used to
calculate the checksum. By default everything before the checksum
result is used.
A Optional. If used, the resulting checksum value is converted into a
readable ASCII text. This is for example used in MODBUS ASCII
protocols.
L Optional. Little Endian - the resulting checksum value is stored with
the least significant byte (LSB) first. Default is Big Endian / MSB first.
@ targetPos
e.g.
Optional. Specifies the first character position for storing the resulting
checksum value.