Create/Edit Characteristics

Characteristics are typically read-write calibrations stored in an ECU. The ASAP2 Editor supports these 3 types:

• Value - a single value with no axis.

• Curve - an array of values with an X axis.

• Map - a table of values with X and Y axes.

To create or edit Characteristics in an A2L file use the Create or Edit tools in the main toolbar or the right click menu while the Characteristics tab is active in the A2L file area. A tabbed dialog will open similar to that shown in Figure 1.

Figure 1: The dialog for creating or editing A2L file Characteristics.

The General tab defines most of the Characteristic properties and these are described in Table 1 below. The Address tab defines memory addressing for the Characteristic. One or both of the Axis tabs will appear if the Type is a curve or map. The Interface Data tab supports unique data that a tool may need to run properly. Use the OK button to close the dialog and save any changes. Use the Cancel button to close the dialog without saving any changes.

Table 1: Characteristic Properties on the General Tab

Property	Description
Name	Unique identifier of the Characteristic. Here are the main requirements for this field: Max overall length = 1024 characters. Max partial string length = 128 characters. Allowed characters: A - Z, a - z, 0 - 9, underscores, periods, and brackets [ ]. Must NOT contain spaces. First character must be a letter or an underscore. Any brackets must occur in pairs at the end of a partial string. Any bracket pairs must surround a number or string. Name is case sensitive. (i.e. "b" and "B" are considered unique) If in doubt about valid names, please refer to the ASAM specifications.
Long Identifier	Comment or description.
ECU Address	Memory address of the Characteristic. Data comes from the Address tab, so use that tab instead to change this data.
Display Identifier	Alternative display name that is usually shorter than the Name property. Useful for devices with small display areas.
Type	The ASAP2 Editor supports these 3 types of Characteristics: Value - a single value with no axis. Curve - an array of values with 1 axis. Map - a table of values with 2 axes.
Record Layout	Specifies the data structure. The default layout will update depending upon the Data Type field. The dropdown selections come from the Record Layouts tab. The Data Type over on the Record Layout tab must match the Data Type field on this dialog.
Conversion Method	Applies the selected Conversion Method to the value. The dropdown selections come from the Conversion Methods tab.
Format	Display formatting applied to numerical values. If specified, this Format property overrides any formatting in the Conversion Method property. The syntax for this field is: %Length.Layout Length = overall length Layout = number of decimal places
Data Type	Determines the number of bytes dedicated to the value and how those bytes are interpreted. This property should be chosen early because it applies defaults to the Record Layout, Lower/Upper Limit, Extended Lower/Upper Limit, and Bitmask properties. UBYTE - 1 byte unsigned integer SBYTE - 1 byte signed integer UWORD - 2 byte unsigned integer SWORD - 2 byte signed integer ULONG - 4 byte unsigned integer SLONG - 4 byte signed integer FLOAT32_IEEE - 4 byte (32 bit) floating point IEEE format FLOAT64_IEEE - 8 byte (64 bit) floating point IEEE format FLOAT32_TASKING - 4 byte (32 bit) floating point tasking format
Calibration Access	There are 4 types of access for MCD systems or test tools: CALIBRATION - read and write allowed. NO_CALIBRATION - read only. NOT_IN_MCD_SYSTEM - read and write not allowed, for internal ECU use only. OFFLINE_CALIBRATION - read allowed, write only allowed offline.
Lower Limit	Lower limit of plausible range of values. A default limit is determined mathematically by the Data Type selection. Note: The default limit is reapplied each time the Data Type is changed.
Upper Limit	Upper limit of plausible range of values. A default limit is determined mathematically by the Data Type selection. Note: The default limit is reapplied each time the Data Type is changed.
Extended Lower Limit	Extends the lower limit of plausible values. Can be useful for generating warnings when the Lower Limit is exceeded. A default limit is determined mathematically by the Data Type selection. Note: The default limit is reapplied each time the Data Type is changed.
Extended Upper Limit	Extends the upper limit of plausible values. Can be useful for generating warnings when the Upper Limit is exceeded. A default limit is determined mathematically by the Data Type selection. Note: The default limit is reapplied each time the Data Type is changed.
Bit Mask	Masks out single bits of the value to be processed. 0xFF = no mask for that byte. This property defaults to no masking with the number of 0xFF's determined by the Data Type selection. Note: The default mask is reapplied each time the Data Type is changed.
Max Diff	Maximum adjustment allowed to the Characteristic. Entered as an absolute value, not as a percentage.