32
Docklight V2.2 User Manual 07/2016 Copyright 2016 Flachmann und Heggelbacher GbR
Working with Docklight (Advanced)
Redundancy Code), which is used in different variations for different protocols. The
following step-by-step example describes how to set up on-the-fly checksum calculation
for a Send Sequence, and how to enable automatic validation of a checksum area within
a Receive Sequence.
TIP: For a working example to address a
slave device, see the tutorial
Preconditions
You know the checksum specification for the protocol messages:
·
Which area of the sequence data is guarded by a checksum?
·
Where is the checksum located? (Usually at the end of the sequence.)
·
What checksum algorithm should be used? (Most likely one of the
, or a simple MOD256 sum.)
Using Send Sequences with automatic checksum calculation
A) Defining a Send Sequence that includes a checksum
1.
. Enter a
Name
for the sequence.
2.
Enter the Sequence part of your message in the
Sequence
section. For example,
here we use a very simple HEX message as our sequence:
01 | 02 | 03 | 04 | ??
Use the context menu via
right mouse button
or
F7
to create the
??
wildcard.
NOTE: See also the
section for more information on
wildcards and parameters.
3.
Now add one additional 00 value as a placeholder for the checksum.
01 | 02 | 03 | 04 | ?? | 00
4.
Go to the
Additional Settings
|
Checksum
tab and
. For
example, here we chose to use
MOD256
from the dropdown list.
NOTE: The text field for Checksum allows comments. Everything behind a
#
character is just a comment. You can add your own comments to describe what
this checksum is about.
5.
Click
OK
to add the new sequence to the Send Sequence list.
B) Performing the test
6. Use the
Send
button to send one of the predefined commands. Enter a
parameter value, e.g. 05.
Before sending the data, Docklight calculates the actual MOD256 checksum. The result
goes to the specified checksum position. For MOD256 this is the last character
position by default, which means that the 00 placeholder is overwritten with the
checksum result.
If we use 05 as a parameter when sending the sequence, the data sent by Docklight will
look like this:
Summary of Contents for Docklight V2.2
Page 1: ...Docklight V2 2 User Manual 07 2016 Copyright 2016 Flachmann und Heggelbacher GbR...
Page 5: ...Copyright...
Page 7: ...Introduction...
Page 11: ...User Interface...
Page 14: ...Features and Functions...
Page 17: ...Working with Docklight...
Page 28: ...Working with Docklight Advanced...
Page 41: ...Examples and Tutorials...
Page 46: ...Reference...
Page 62: ...Support...
Page 64: ...Appendix...
Page 76: ...76 Docklight V2 2 User Manual 07 2016 Copyright 2016 Flachmann und Heggelbacher GbR Appendix...
Page 77: ...Glossary Terms Used...
