CANoe DENoe - KEMT FEI TUKE

time stamp
2.7000 sec
CANoe transmit
branch
Tx buffer of
the controller
2.7400 sec
CAN-Bus
trace window
2.7000 1 3FC TxRq d 3 29 10 98
trace window
Figure 54: Transmission of messages
2.7400 1 3FC Tx d 3 29 10 98
The TxRq display permits measurements of the difference between the time of
transmit request and time of transmission. The time between the message with Tx
attribute and TxRq attribute is essentially the transmission time of a message, i.e. the
time that the CAN controller needs to place a message completely on the bus. It is a
function of baud rate and message length. The transmission time also grows as a
result of lost arbitration events, which can be observed more for low-priority messages
at high bus loads.
Since the (very small) latency time of the card driver interrupt must be added to the
transmission time, the following general formula applies:
tTx - tTxRq = Transmission time + Latency time
Note: Under high load conditions the display of messages might be delayed in
the evaluation windows under some circumstances. However, the time
stamps for the messages remain unaffected by this, since they are already
assigned to the messages when they are received on the card.
3.2.5 Simulation Mode
At the beginning of the development process, the network is fully simulated. In this
phase you can operate CANoe with or without a physical bus. In the former case it is
sufficient to connect the card's two CAN controllers to the bus. In this case the operating
mode in the simulation dialog (Main menu item Configuration│Simulation)
remains set to Real Bus. All messages generated in the simulation setup are then
placed on the real bus by the first chip. Here the second chip only serves as a second
bus station which permits the operation of a real bus.
© Vector Informatik GmbH CANoe/DENoe Manual Version 4.1.1
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