CAN analyzer

CAN analyzer I/O The CAN analyzer I/O decodes analog data to CAN data. The source of the analyzer can either be the differential CAN signal (preferred) or the CAN-high signal. The decoded fields can be shown in a Data grid sink.

The following fields are extracted from the CAN data by the analyzer:

Field name Purpose
Identifier (ID) A (unique) identifier for the data
Remote transmission request (RTR) If 1, remote data is requested
Identifier extension bit (IDE) If 1, the ID consists of 29 instead of 11 bits
Reserved bit (R1) Reserved bit, only in extended format
Reserved bit (R0) Reserved bit (it must be set to dominant (0), but accepted as either dominant or recessive)
Data length code (DLC)* Number of bytes of data (0-8 bytes)
Data Transmitted data (length dictated by DLC field)
CRC Cyclic Redundancy Check
CRC delimiter Must be recessive (1)
Acknowledged Indicates whether the message was acknowledged
ACK delimiter Must be recessive (1)
Errors Any errors detected in the message

An example of analyzed CAN data is shown below.

CAN analyzer example Measurement on a CAN bus in a car, with decoded CAN data.

Properties and actions

To control the behavior of the CAN analyzer I/O, several properties are available. These can be accessed through a popup menu which is shown when the I/O is right clicked.

Bitrate

For correct detection, the Bitrate property must be set to the correct value corresponding to the bus that is under measurement. It can be set to several common values, but also to a user defined value.

MidLevel

For signal edge detection, the CAN analyzer uses a level to which the signal is compared: all signal parts above this level are considered "high", all signal parts below this level are considered "low". The default value for the MidLevel property is 0.7 Volt.

Common properties and actions

Alias

You can change the displayed name of an object by giving it an Alias. This can be handy when you are dealing with a lot of objects and have problems keeping them apart. You can for example give channel one of your instrument the alias "Battery", when it is measuring a battery voltage. To give an object an alias, use the item Alias ... in its menu. To remove an alias and revert to the original name of the object, set the alias to an empty string.

Color

When multiple sources or I/O's are displayed in a graph or a meter, they can be distinguished from each other by their Color. Three different color settings are available for a source or an I/O.

  • Automatic
    A color is selected from a group of colors. There are separate groups for channel colors and source colors. The groups can be configured in the program settings. Each new channel or source uses the next available color in the group. When the last color in the group is used and another channel or source is added, picking will start at the top of the group again.
  • As source
    This setting is only available for I/O's. The I/O will use the same color as its source. When multiple sources are connected to the I/O, the color of the first connected source is used.
  • User defined...
    The color of the source or I/O is user selected, using a color picker dialog. Any color can be used.

Disconnect all sources

To disconnect all sources from an I/O or Sink at once, use the Disconnect all sources action.

Disconnect sink(s)

To disconnect one or more sinks from an I/O or Source, use the Disconnect sink(s) action. This will show a dialog that lists all connected sinks. Individual sinks can then be selected and disconnected from the object.

Disconnect all sinks

To disconnect all sinks from an I/O or source at once, use the Disconnect all sinks action.

Clone

When a new object is to be created, similar to an already existing object, with the same properties, the Clone action can be used. This will create an identical copy of the original object, with the exact same properties. Source(s) and sink(s) of the new object are not yet connected.

Delete

The Delete action deletes a source, I/O or sink. All connections of the object will be disconnected and then the object will be removed from the object tree. The source property of the objects that used this object as source will be cleared. The sink property of the objects that used this object as sink will be cleared. An axis in a graph that was connected to this object will be also deleted.

Export data

The Export data action allows to export the data of an object to a file. This is detailed described on the page about Exporting data.

Load

The Load action allows to load the settings and data for an object from a TPS or TPO file. This is detailed described on the page about Loading into selected objects.

Save as

The Save as action allows to save the settings and data of one or more objects to a TPO file. When multiple objects are selected, the connections between the objects are saved as well. This is detailed described on the page about Saving objects to a TPO file.