The Packer component implements repacking of AIDA_tstEvents according
to length information or special start codes contained
in the data part of the AIDA_tstEvents.
It can be used if data streams have been divided into AIDA_tstEvents at
wrong places. The Packer component collects AIDA_tstEvents of the
AIDA_tenEventType AIDA_nenReceiveData
in a buffer until enough data is available to create a new AIDA_tstEvent with
the number of data bytes found out in the data part.
Parameters
-
HeaderFlags (Broadcast Parameter)
-
Field of flags for special treatment of the header.
| 0x0000000FUL |
SpecialModeMask |
these bits are reserved for modes which require special treatment of the header (e.g. KWP 2000). |
| 0x00000040UL |
ExcludeFrameLengthMask |
this bit is used for the calculation of the length information in the header. |
| 0x00000040UL |
ExcludeFrameLength |
when set indicates, that the length of the frame is excluded from the calculation of the telegram length. |
The currently implemented special modes are:
| 0x00000000UL |
SpecialModeNone |
There is no special treatment. |
| 0x00000001UL |
SpecialModeKWP2000COM |
KWP2000 headers are used as defined in ISO 14230. |
| 0x00000002UL |
SpecialModeKWP2000CAN |
KWP2000 over CAN is used. (2 byte header with 12 bit length info). |
| 0x00000003UL |
SpecialModeDS2 |
The ECU ID is generated as described in DS2 documentation (currently unimplemented). |
When a special mode is selected, other parameters are modified according to the specs and
can't be changed by the user anymore. These parameters are:
LengthWidth,
LengthPos, and LengthMask.
-
LengthWidth
-
Specifies how many bytes are used to transmit the telegram length.
-
LengthPos
-
Specifies the position of the length information in the telegram.
Values ≤ 0 mean, that there is no length information in the header.
-
LengthOffset
-
Offset to be added to the length of the telegram to calculate
the length information included in the header.
If ExcludeFrameLength in the HeaderFlags
is set:
telegram length (excluding header) + LengthOffset = length information in the telegram
If ExcludeFrameLength in the HeaderFlags
is not set:
telegram length (including header) + LengthOffset = length information in the telegram
-
LengthMask
-
Mask to be used when merging length information and other information (e.g.
like in the Format byte of KWP2000). If the Mask = 0 it is ignored, otherwise bits
set in the mask mark this area as useable for the length information (The LengthMask is anded bitwise with the calculated length).
The LengthMask doesn't imply any bit shifts.
-
IntermessageTimeout
-
Specifies how long the component waits for consecutive AIDA_nenReceiveData Events
until it creates a new Event with the data still contained in the buffer. If no additional data is expected according to the length info, no
new Events are created. Units used are ms.
-
StartCode
-
Code to identify the start of a new message. If the StartCode is found in the
data part of an AIDA_tstEvent, the data before
and after the StartCode are split and put into separate AIDA_tstEvents.
The StartCode has to be different from the EscapeCode.
Evaluation of StartCode is controlled by EscapeFlags.
-
EscapeCode
-
Code to identify the start of an escaped sequence. This code has to be different from the StartCode.
Evaluation of EscapeCode is controlled by EscapeFlags.
-
EscapeFlags
-
Field of flags to control if and how StartCode
and EscapeCode are interpreted.
| 0x00000001UL |
UseSTX |
Is STX detection and encoding/decoding of escape sequences active. |
See Also
AIDA Overview, list of AIDA components,
AIDA Structures And Datatypes, AIDA_tenEventType