# coding: utf-8
"""
Ctypes wrapper module for Vector CAN Interface on win32/win64 systems.
Authors: Julien Grave <grave.jul@gmail.com>, Christian Sandberg
"""
# Import Standard Python Modules
# ==============================
import ctypes
import logging
import sys
import time
try:
# Try builtin Python 3 Windows API
from _winapi import WaitForSingleObject, INFINITE
HAS_EVENTS = True
except ImportError:
try:
# Try pywin32 package
from win32event import WaitForSingleObject, INFINITE
HAS_EVENTS = True
except ImportError:
# Use polling instead
HAS_EVENTS = False
# Import Modules
# ==============
from can import BusABC, Message, CanError
from can.util import len2dlc, dlc2len
from .exceptions import VectorError
# Define Module Logger
# ====================
LOG = logging.getLogger(__name__)
# Import safely Vector API module for Travis tests
vxlapi = None
try:
from . import vxlapi
except Exception as exc:
LOG.warning('Could not import vxlapi: %s', exc)
[docs]class VectorBus(BusABC):
"""The CAN Bus implemented for the Vector interface."""
def __init__(self, channel, can_filters=None, poll_interval=0.01,
receive_own_messages=False,
bitrate=None, rx_queue_size=2**14, app_name="CANalyzer", serial=None, fd=False, data_bitrate=None, sjwAbr=2, tseg1Abr=6, tseg2Abr=3, sjwDbr=2, tseg1Dbr=6, tseg2Dbr=3, **config):
"""
:param list channel:
The channel indexes to create this bus with.
Can also be a single integer or a comma separated string.
:param float poll_interval:
Poll interval in seconds.
:param int bitrate:
Bitrate in bits/s.
:param int rx_queue_size:
Number of messages in receive queue (power of 2).
CAN: range 16…32768
CAN-FD: range 8192…524288
:param str app_name:
Name of application in Hardware Config.
If set to None, the channel should be a global channel index.
:param int serial:
Serial number of the hardware to be used.
If set, the channel parameter refers to the channels ONLY on the specified hardware.
If set, the app_name is unused.
:param bool fd:
If CAN-FD frames should be supported.
:param int data_bitrate:
Which bitrate to use for data phase in CAN FD.
Defaults to arbitration bitrate.
"""
if vxlapi is None:
raise ImportError("The Vector API has not been loaded")
self.poll_interval = poll_interval
if isinstance(channel, (list, tuple)):
self.channels = channel
elif isinstance(channel, int):
self.channels = [channel]
else:
# Assume comma separated string of channels
self.channels = [int(ch.strip()) for ch in channel.split(',')]
self._app_name = app_name.encode()
self.channel_info = 'Application %s: %s' % (
app_name, ', '.join('CAN %d' % (ch + 1) for ch in self.channels))
if serial is not None:
app_name = None
channel_index = []
channel_configs = get_channel_configs()
for channel_config in channel_configs:
if channel_config.serialNumber == serial:
if channel_config.hwChannel in self.channels:
channel_index.append(channel_config.channelIndex)
if len(channel_index) > 0:
if len(channel_index) != len(self.channels):
LOG.info("At least one defined channel wasn't found on the specified hardware.")
self.channels = channel_index
else:
# Is there any better way to raise the error?
raise Exception("None of the configured channels could be found on the specified hardware.")
vxlapi.xlOpenDriver()
self.port_handle = vxlapi.XLportHandle(vxlapi.XL_INVALID_PORTHANDLE)
self.mask = 0
self.fd = fd
# Get channels masks
self.channel_masks = {}
self.index_to_channel = {}
for channel in self.channels:
if app_name:
# Get global channel index from application channel
hw_type = ctypes.c_uint(0)
hw_index = ctypes.c_uint(0)
hw_channel = ctypes.c_uint(0)
vxlapi.xlGetApplConfig(self._app_name, channel, hw_type, hw_index,
hw_channel, vxlapi.XL_BUS_TYPE_CAN)
LOG.debug('Channel index %d found', channel)
idx = vxlapi.xlGetChannelIndex(hw_type.value, hw_index.value,
hw_channel.value)
if idx < 0:
# Undocumented behavior! See issue #353.
# If hardware is unavailable, this function returns -1.
# Raise an exception as if the driver
# would have signalled XL_ERR_HW_NOT_PRESENT.
raise VectorError(vxlapi.XL_ERR_HW_NOT_PRESENT,
"XL_ERR_HW_NOT_PRESENT",
"xlGetChannelIndex")
else:
# Channel already given as global channel
idx = channel
mask = 1 << idx
self.channel_masks[channel] = mask
self.index_to_channel[idx] = channel
self.mask |= mask
permission_mask = vxlapi.XLaccess()
# Set mask to request channel init permission if needed
if bitrate or fd:
permission_mask.value = self.mask
if fd:
vxlapi.xlOpenPort(self.port_handle, self._app_name, self.mask,
permission_mask, rx_queue_size,
vxlapi.XL_INTERFACE_VERSION_V4, vxlapi.XL_BUS_TYPE_CAN)
else:
vxlapi.xlOpenPort(self.port_handle, self._app_name, self.mask,
permission_mask, rx_queue_size,
vxlapi.XL_INTERFACE_VERSION, vxlapi.XL_BUS_TYPE_CAN)
LOG.debug(
'Open Port: PortHandle: %d, PermissionMask: 0x%X',
self.port_handle.value, permission_mask.value)
if permission_mask.value == self.mask:
if fd:
self.canFdConf = vxlapi.XLcanFdConf()
if bitrate:
self.canFdConf.arbitrationBitRate = ctypes.c_uint(bitrate)
else:
self.canFdConf.arbitrationBitRate = ctypes.c_uint(500000)
self.canFdConf.sjwAbr = ctypes.c_uint(sjwAbr)
self.canFdConf.tseg1Abr = ctypes.c_uint(tseg1Abr)
self.canFdConf.tseg2Abr = ctypes.c_uint(tseg2Abr)
if data_bitrate:
self.canFdConf.dataBitRate = ctypes.c_uint(data_bitrate)
else:
self.canFdConf.dataBitRate = self.canFdConf.arbitrationBitRate
self.canFdConf.sjwDbr = ctypes.c_uint(sjwDbr)
self.canFdConf.tseg1Dbr = ctypes.c_uint(tseg1Dbr)
self.canFdConf.tseg2Dbr = ctypes.c_uint(tseg2Dbr)
vxlapi.xlCanFdSetConfiguration(self.port_handle, self.mask, self.canFdConf)
LOG.info('SetFdConfig.: ABaudr.=%u, DBaudr.=%u', self.canFdConf.arbitrationBitRate, self.canFdConf.dataBitRate)
LOG.info('SetFdConfig.: sjwAbr=%u, tseg1Abr=%u, tseg2Abr=%u', self.canFdConf.sjwAbr, self.canFdConf.tseg1Abr, self.canFdConf.tseg2Abr)
LOG.info('SetFdConfig.: sjwDbr=%u, tseg1Dbr=%u, tseg2Dbr=%u', self.canFdConf.sjwDbr, self.canFdConf.tseg1Dbr, self.canFdConf.tseg2Dbr)
else:
if bitrate:
vxlapi.xlCanSetChannelBitrate(self.port_handle, permission_mask, bitrate)
LOG.info('SetChannelBitrate: baudr.=%u',bitrate)
else:
LOG.info('No init access!')
# Enable/disable TX receipts
tx_receipts = 1 if receive_own_messages else 0
vxlapi.xlCanSetChannelMode(self.port_handle, self.mask, tx_receipts, 0)
if HAS_EVENTS:
self.event_handle = vxlapi.XLhandle()
vxlapi.xlSetNotification(self.port_handle, self.event_handle, 1)
else:
LOG.info('Install pywin32 to avoid polling')
try:
vxlapi.xlActivateChannel(self.port_handle, self.mask,
vxlapi.XL_BUS_TYPE_CAN, 0)
except VectorError:
self.shutdown()
raise
# Calculate time offset for absolute timestamps
offset = vxlapi.XLuint64()
vxlapi.xlGetSyncTime(self.port_handle, offset)
self._time_offset = time.time() - offset.value * 1e-9
self._is_filtered = False
super(VectorBus, self).__init__(channel=channel, can_filters=can_filters,
**config)
def _apply_filters(self, filters):
if filters:
# Only up to one filter per ID type allowed
if len(filters) == 1 or (len(filters) == 2 and
filters[0].get("extended") != filters[1].get("extended")):
try:
for can_filter in filters:
vxlapi.xlCanSetChannelAcceptance(self.port_handle, self.mask,
can_filter["can_id"], can_filter["can_mask"],
vxlapi.XL_CAN_EXT if can_filter.get("extended") else vxlapi.XL_CAN_STD)
except VectorError as exc:
LOG.warning("Could not set filters: %s", exc)
# go to fallback
else:
self._is_filtered = True
return
else:
LOG.warning("Only up to one filter per extended or standard ID allowed")
# go to fallback
# fallback: reset filters
self._is_filtered = False
try:
vxlapi.xlCanSetChannelAcceptance(self.port_handle, self.mask, 0x0, 0x0, vxlapi.XL_CAN_EXT)
vxlapi.xlCanSetChannelAcceptance(self.port_handle, self.mask, 0x0, 0x0, vxlapi.XL_CAN_STD)
except VectorError as exc:
LOG.warning("Could not reset filters: %s", exc)
def _recv_internal(self, timeout):
end_time = time.time() + timeout if timeout is not None else None
if self.fd:
event = vxlapi.XLcanRxEvent()
else:
event = vxlapi.XLevent()
event_count = ctypes.c_uint()
while True:
if self.fd:
try:
vxlapi.xlCanReceive(self.port_handle, event)
except VectorError as exc:
if exc.error_code != vxlapi.XL_ERR_QUEUE_IS_EMPTY:
raise
else:
if event.tag == vxlapi.XL_CAN_EV_TAG_RX_OK or event.tag == vxlapi.XL_CAN_EV_TAG_TX_OK:
msg_id = event.tagData.canRxOkMsg.canId
dlc = dlc2len(event.tagData.canRxOkMsg.dlc)
flags = event.tagData.canRxOkMsg.msgFlags
timestamp = event.timeStamp * 1e-9
channel = self.index_to_channel.get(event.chanIndex)
msg = Message(
timestamp=timestamp + self._time_offset,
arbitration_id=msg_id & 0x1FFFFFFF,
is_extended_id=bool(msg_id & vxlapi.XL_CAN_EXT_MSG_ID),
is_remote_frame=bool(flags & vxlapi.XL_CAN_RXMSG_FLAG_RTR),
is_error_frame=bool(flags & vxlapi.XL_CAN_RXMSG_FLAG_EF),
is_fd=bool(flags & vxlapi.XL_CAN_RXMSG_FLAG_EDL),
error_state_indicator=bool(flags & vxlapi.XL_CAN_RXMSG_FLAG_ESI),
bitrate_switch=bool(flags & vxlapi.XL_CAN_RXMSG_FLAG_BRS),
dlc=dlc,
data=event.tagData.canRxOkMsg.data[:dlc],
channel=channel)
return msg, self._is_filtered
else:
event_count.value = 1
try:
vxlapi.xlReceive(self.port_handle, event_count, event)
except VectorError as exc:
if exc.error_code != vxlapi.XL_ERR_QUEUE_IS_EMPTY:
raise
else:
if event.tag == vxlapi.XL_RECEIVE_MSG:
msg_id = event.tagData.msg.id
dlc = event.tagData.msg.dlc
flags = event.tagData.msg.flags
timestamp = event.timeStamp * 1e-9
channel = self.index_to_channel.get(event.chanIndex)
msg = Message(
timestamp=timestamp + self._time_offset,
arbitration_id=msg_id & 0x1FFFFFFF,
is_extended_id=bool(msg_id & vxlapi.XL_CAN_EXT_MSG_ID),
is_remote_frame=bool(flags & vxlapi.XL_CAN_MSG_FLAG_REMOTE_FRAME),
is_error_frame=bool(flags & vxlapi.XL_CAN_MSG_FLAG_ERROR_FRAME),
is_fd=False,
dlc=dlc,
data=event.tagData.msg.data[:dlc],
channel=channel)
return msg, self._is_filtered
if end_time is not None and time.time() > end_time:
return None, self._is_filtered
if HAS_EVENTS:
# Wait for receive event to occur
if timeout is None:
time_left_ms = INFINITE
else:
time_left = end_time - time.time()
time_left_ms = max(0, int(time_left * 1000))
WaitForSingleObject(self.event_handle.value, time_left_ms)
else:
# Wait a short time until we try again
time.sleep(self.poll_interval)
[docs] def send(self, msg, timeout=None):
msg_id = msg.arbitration_id
if msg.is_extended_id:
msg_id |= vxlapi.XL_CAN_EXT_MSG_ID
flags = 0
# If channel has been specified, try to send only to that one.
# Otherwise send to all channels
mask = self.channel_masks.get(msg.channel, self.mask)
if self.fd:
if msg.is_fd:
flags |= vxlapi.XL_CAN_TXMSG_FLAG_EDL
if msg.bitrate_switch:
flags |= vxlapi.XL_CAN_TXMSG_FLAG_BRS
if msg.is_remote_frame:
flags |= vxlapi.XL_CAN_TXMSG_FLAG_RTR
message_count = 1
MsgCntSent = ctypes.c_uint(1)
XLcanTxEvent = vxlapi.XLcanTxEvent()
XLcanTxEvent.tag = vxlapi.XL_CAN_EV_TAG_TX_MSG
XLcanTxEvent.transId = 0xffff
XLcanTxEvent.tagData.canMsg.canId = msg_id
XLcanTxEvent.tagData.canMsg.msgFlags = flags
XLcanTxEvent.tagData.canMsg.dlc = len2dlc(msg.dlc)
for idx, value in enumerate(msg.data):
XLcanTxEvent.tagData.canMsg.data[idx] = value
vxlapi.xlCanTransmitEx(self.port_handle, mask, message_count, MsgCntSent, XLcanTxEvent)
else:
if msg.is_remote_frame:
flags |= vxlapi.XL_CAN_MSG_FLAG_REMOTE_FRAME
message_count = ctypes.c_uint(1)
xl_event = vxlapi.XLevent()
xl_event.tag = vxlapi.XL_TRANSMIT_MSG
xl_event.tagData.msg.id = msg_id
xl_event.tagData.msg.dlc = msg.dlc
xl_event.tagData.msg.flags = flags
for idx, value in enumerate(msg.data):
xl_event.tagData.msg.data[idx] = value
vxlapi.xlCanTransmit(self.port_handle, mask, message_count, xl_event)
[docs] def flush_tx_buffer(self):
vxlapi.xlCanFlushTransmitQueue(self.port_handle, self.mask)
[docs] def shutdown(self):
vxlapi.xlDeactivateChannel(self.port_handle, self.mask)
vxlapi.xlClosePort(self.port_handle)
vxlapi.xlCloseDriver()
def reset(self):
vxlapi.xlDeactivateChannel(self.port_handle, self.mask)
vxlapi.xlActivateChannel(self.port_handle, self.mask,
vxlapi.XL_BUS_TYPE_CAN, 0)
@staticmethod
def _detect_available_configs():
configs = []
channel_configs = get_channel_configs()
LOG.info('Found %d channels', len(channel_configs))
for channel_config in channel_configs:
LOG.info('Channel index %d: %s',
channel_config.channelIndex,
channel_config.name.decode('ascii'))
configs.append({'interface': 'vector',
'app_name': None,
'channel': channel_config.channelIndex})
return configs
def get_channel_configs():
if vxlapi is None:
return []
driver_config = vxlapi.XLdriverConfig()
try:
vxlapi.xlOpenDriver()
vxlapi.xlGetDriverConfig(driver_config)
vxlapi.xlCloseDriver()
except:
pass
return [driver_config.channel[i] for i in range(driver_config.channelCount)]