IXXAT Virtual CAN Interface

Interface to IXXAT Virtual CAN Interface V3 SDK. Works on Windows.

The Linux ECI SDK is currently unsupported, however on Linux some devices are supported with SocketCAN.

The send_periodic() method is supported natively through the on-board cyclic transmit list. Modifying cyclic messages is not possible. You will need to stop it, and then start a new periodic message.

Bus

Configuration file

The simplest configuration file would be:

[default]
interface = ixxat
channel = 0

Python-can will search for the first IXXAT device available and open the first channel. interface and channel parameters are interpreted by frontend can.interfaces.interface module, while the following parameters are optional and are interpreted by IXXAT implementation.

  • receive_own_messages (default False) Enable self-reception of sent messages.

  • unique_hardware_id (default first device) Unique hardware ID of the IXXAT device.

  • extended (default True) Allow usage of extended IDs.

  • fd (default False) Enable CAN-FD capabilities.

  • rx_fifo_size (default 16 for CAN, 1024 for CAN-FD) Number of RX mailboxes.

  • tx_fifo_size (default 16 for CAN, 128 for CAN-FD) Number of TX mailboxes.

  • bitrate (default 500000) Channel bitrate.

  • data_bitrate (defaults to 2Mbps) Channel data bitrate (only canfd, to use when message bitrate_switch is used).

  • sjw_abr (optional, only canfd) Bus timing value sample jump width (arbitration).

  • tseg1_abr (optional, only canfd) Bus timing value tseg1 (arbitration).

  • tseg2_abr (optional, only canfd) Bus timing value tseg2 (arbitration).

  • sjw_dbr (optional, only used if baudrate switch enabled) Bus timing value sample jump width (data).

  • tseg1_dbr (optional, only used if baudrate switch enabled) Bus timing value tseg1 (data).

  • tseg2_dbr (optional, only used if baudrate switch enabled) Bus timing value tseg2 (data).

  • ssp_dbr (optional, only used if baudrate switch enabled) Secondary sample point (data).

Filtering

The CAN filters act as an allow list in IXXAT implementation, that is if you supply a non-empty filter list you must explicitly state EVERY frame you want to receive (including RTR field). The can_id/mask must be specified according to IXXAT behaviour, that is bit 0 of can_id/mask parameters represents the RTR field in CAN frame. See IXXAT VCI documentation, section “Message filters” for more info.

List available devices

In case you have connected multiple IXXAT devices, you have to select them by using their unique hardware id. To get a list of all connected IXXAT you can use the function get_ixxat_hwids() as demonstrated below:

>>> from can.interfaces.ixxat import get_ixxat_hwids
>>> for hwid in get_ixxat_hwids():
...     print("Found IXXAT with hardware id '%s'." % hwid)
Found IXXAT with hardware id 'HW441489'.
Found IXXAT with hardware id 'HW107422'.

Internals

The IXXAT BusABC object is a fairly straightforward interface to the IXXAT VCI library. It can open a specific device ID or use the first one found.

The frame exchange does not involve threads in the background but is explicitly instantiated by the caller.

  • recv() is a blocking call with optional timeout.

  • send() is not blocking but may raise a VCIError if the TX FIFO is full

RX and TX FIFO sizes are configurable with rx_fifo_size and tx_fifo_size options, defaulting to 16 for both.