Handle timer overflow message and build timestamp according to the epoch

can/interfaces/ixxat/canlib_vcinpl.py

@@ -13,6 +13,7 @@
 import functools
 import logging
 import sys
+import time
 import warnings
 from typing import Callable, List, Optional, Sequence, Tuple, Union
 
@@ -619,7 +620,15 @@ def __init__(
  log.info("Accepting ID: 0x%X MASK: 0x%X", code, mask)
 
  # Start the CAN controller. Messages will be forwarded to the channel
+ start_begin = time.time()
  _canlib.canControlStart(self._control_handle, constants.TRUE)
+ start_end = time.time()
+
+ # Calculate an offset to make them relative to epoch
+ # Assume that the time offset is in the middle of the start command
+ self._timeoffset = start_begin + (start_end - start_begin / 2)
+ self._overrunticks = 0
+ self._starttickoffset = 0
 
  # For cyclic transmit list. Set when .send_periodic() is first called
  self._scheduler = None
@@ -692,6 +701,9 @@ def _recv_internal(self, timeout):
  f"Unknown CAN info message code {self._message.abData[0]}",
  )
  )
+ # Handle CAN start info message
+ if self._message.abData[0] == constants.CAN_INFO_START:
+ self._starttickoffset = self._message.dwTime
  elif self._message.uMsgInfo.Bits.type == constants.CAN_MSGTYPE_ERROR:
  if self._message.uMsgInfo.Bytes.bFlags & constants.CAN_MSGFLAGS_OVR:
  log.warning("CAN error: data overrun")
@@ -708,7 +720,8 @@ def _recv_internal(self, timeout):
  self._message.uMsgInfo.Bytes.bFlags,
  )
  elif self._message.uMsgInfo.Bits.type == constants.CAN_MSGTYPE_TIMEOVR:
- pass
+ # Add the number of timestamp overruns to the high word
+ self._overrunticks += self._message.dwMsgId << 32
  else:
  log.warning(
  "Unexpected message info type 0x%X",
@@ -740,11 +753,12 @@ def _recv_internal(self, timeout):
  # Timed out / can message type is not DATA
  return None, True
 
- # The _message.dwTime is a 32bit tick value and will overrun,
- # so expect to see the value restarting from 0
  rx_msg = Message(
- timestamp=self._message.dwTime
- / self._tick_resolution, # Relative time in s
+ timestamp=(
+ (self._message.dwTime + self._overrunticks - self._starttickoffset)
+ / self._tick_resolution
+ )
+ + self._timeoffset,
  is_remote_frame=bool(self._message.uMsgInfo.Bits.rtr),
  is_extended_id=bool(self._message.uMsgInfo.Bits.ext),
  arbitration_id=self._message.dwMsgId,

can/interfaces/ixxat/canlib_vcinpl2.py

@@ -726,7 +726,15 @@ def __init__(
  log.info("Accepting ID: 0x%X MASK: 0x%X", code, mask)
 
  # Start the CAN controller. Messages will be forwarded to the channel
+ start_begin = time.time()
  _canlib.canControlStart(self._control_handle, constants.TRUE)
+ start_end = time.time()
+
+ # Calculate an offset to make them relative to epoch
+ # Assume that the time offset is in the middle of the start command
+ self._timeoffset = start_begin + (start_end - start_begin / 2)
+ self._overrunticks = 0
+ self._starttickoffset = 0
 
  # For cyclic transmit list. Set when .send_periodic() is first called
  self._scheduler = None
@@ -831,7 +839,9 @@ def _recv_internal(self, timeout):
  f"Unknown CAN info message code {self._message.abData[0]}",
  )
  )
-
+ # Handle CAN start info message
+ elif self._message.abData[0] == constants.CAN_INFO_START:
+ self._starttickoffset = self._message.dwTime
  elif (
  self._message.uMsgInfo.Bits.type == constants.CAN_MSGTYPE_ERROR
  ):
@@ -853,7 +863,8 @@ def _recv_internal(self, timeout):
  self._message.uMsgInfo.Bits.type
  == constants.CAN_MSGTYPE_TIMEOVR
  ):
- pass
+ # Add the number of timestamp overruns to the high word
+ self._overrunticks += self._message.dwMsgId << 32
  else:
  log.warning("Unexpected message info type")
 
@@ -867,11 +878,12 @@ def _recv_internal(self, timeout):
  return None, True
 
  data_len = dlc2len(self._message.uMsgInfo.Bits.dlc)
- # The _message.dwTime is a 32bit tick value and will overrun,
- # so expect to see the value restarting from 0
  rx_msg = Message(
- timestamp=self._message.dwTime
- / self._tick_resolution, # Relative time in s
+ timestamp=(
+ (self._message.dwTime + self._overrunticks - self._starttickoffset)
+ / self._tick_resolution
+ )
+ + self._timeoffset,
  is_remote_frame=bool(self._message.uMsgInfo.Bits.rtr),
  is_fd=bool(self._message.uMsgInfo.Bits.edl),
  is_rx=True,