Editing database channel parameters

Only Vector CAN DBC files can be edited at this time.

NOTE
The current offering is for advanced users who understand CAN sufficiently to generate a valid CAN database file. Channel parameters currently have limited validations.

NOTE
Edited CAN databases can be exported in a simplified Vector CAN DBC file format. This is provided primarily for portability from one eDAQXR, eDAQXR-lite or CX23-R device to another. The exported DBC file is not guaranteed to be usable by Vector applications (e.g., CANalyzer, CANape, etc.). The user interface does not validate all user edits that can result in the Vector applications rejecting the exported DBC file. For example, in Vector applications, a Signal or Message name is only valid using letters, numbers and underscores (_).

Database channel content may be edited using the spreadsheet grid cells, or by using the Single channel editor dialog window invoked by clicking on the Edit button in the task pane.

Single channel editor for CAN database channels

Right click on a channel and select Edit from the dropdown menu.

A dialog shows editable parameters.

  • Name: Typically, this is the Channel name and also the Vector CAN DBC file Signal name. However, if the database was imported using the option to prepend the Message name to the Signal name using a delimiter, channels that are edited (or added) must conform to this name format. To be compatible with Vector applications, use only letters, numbers and underscores (_).
  • Message ID: Enter a valid value in hexadecimal format limited to 29 bit significance.
  • Description: There are no restrictions on user input for this.
  • Message name: This must be consistent across all channels that have the same Message ID. To be compatible with Vector applications, use only letters, numbers and underscores (_).
  • Message ID: Enter a valid value in hexadecimal format limited to 29 bit significance. The user interface provides limited validations on this value.
  • Mask: Use FFFFFFFF by default. For advanced users, enter an appropriate value in hexadecimal format in the range of 0 to FFFFFFFF.
  • Bit start, Bit length: The user must provide valid values. Basic validations are performed (e.g., the Bit length currently cannot exceed 64).
  • Offset, Scale: The user must provide valid values. The Scale cannot be 0.0.
  • Min, Max: The user must provide valid values. The only validation is that the Max exceed the Min. However, the user should consider the following. These values are used to set the Range Min/Max parameters when a CAN channel is added to an SXR test. It is recommended that they be set to the actual maximum and minimum values based on the Data format, Scale and Offset values for integer data formats. For example, if the Data format is an Unsigned 16, Max is computed as 32767.0 * Scale + Offset, and Min is computed as -32768.0 * Scale + Offset.
  • Units: There are no restrictions on user input for this. To be compatible with Vector applications, use only letters, numbers and underscores (_).
  • Data format: Select from the Data format pull down (SLSB, UMSB, ULSB, SMSB, FMSB or FLSB). For more information, see Table 2, CAN data type parameters in SIE file metadata.
  • Invalid value: There are no restrictions on this value. However, it is currently advised that this be set to the Max or Min value for channels that use any of the integer Data format options, assuming the Max or Min value is defined using the recommendation provided above.

Mode dependent channels/signals are supported for Basic signal multiplexing. Extended multiplexing is not supported (i.e., there can be only one Multiplexor channel/signal for any given Message ID). The user interface validates this limitation. The following parameters can viewed/edited in the Single channel editor only.

  • Mode dependent type: Select the radio button to define the channel as a Multiplexor channel/signal or a Multiplexed channel/signal when applicable.

If the channel is a Multiplexor channel/signal, there are no other associated parameters. If the channel is a Multiplexed channel/signal, the following parameters are required.

  • Mode bit start, Mode bit length, Mode data format: All three of these parameter values must be the same as the Bit start, Bit Length, Data format values defined for the Multiplexor channel signal. The user interface validates this requirement. The reason these parameters are required is that the system does not require that the Multiplexor channel exist in the database or the SXR channel set; however, it must exist in the database channel set to be able to export the database to a Vector CAN DBC file.
  • Mode value: Enter the Multiplexor value used to identify that the CAN message is providing data for this specific Multiplexer channel/signal. The user interface validates this value. It must be a non-negative integer in the range of the Multiplexor signal. For example, if the Multiplexor signal is Unsigned 8 bit, then it must be in the range of 0 to 255, and if the Multiplexor signal is Signed 8 bit, then it must be in the range of 0 to 127.

CCP channels/signals are supported to a limited (introductory) degree for the eDAQXR and eDAQXR-lite only. CAN databases with any CCP channels/signals cannot be exported.

  • CCP station key: This is a read only temporary identifier used to denote that the channel is a CCP sourced channel. The value shown has no meaning for users. (It will be replaced in the next revision with a different identifier.)

When editing is completed, click OK. The information entered in the dialog will show in the spreadsheet grid cells.