UM-0086-A2
CANgate User’s Manual
Page 34
Watch
the
RS232 Rx
and
RS232 Tx
LEDs when you send the
VERSION
command. They should both flash briefly to
indicate reception of the command and transmission of the response.
If you are using a USB to RS232 converter, check whether its Tx and Rx LEDs flash. If the converter's TX LED doesn't
flash then either you are talking to the wrong COM port, or CANgate has signalled the host to stop sending. Double
check the flow control settings on both devices, and try closing then reopening the connection in DeTransfer.
CAN Bus Errors are reported
Check that the bit rate you have set using the
CONNECT
command matches the bit rate in use on the CAN network.
Check that the polarity of the network connection is correct (CAN-HI signal connected to CAN1-Hi or CAN2-Hi on
CANgate).
Check that the CAN network is correctly terminated. This may require the addition of a terminating resistor, see
Check that the CAN network you are connecting to is actually a
high speed
(ISO 11898-2) CAN network.
If CANgate is configured to send CAN frames, verify that there is at least one other CAN device connected and
operating at the correct bit rate. A bus error will result if a transmitted CAN frame is not properly acknowledged by the
receiving device.
Errors occur when sending a large program to CANgate
Check flow control settings on CANgate and host computer or data logger. Note that DT80 series data loggers with
firmware version less than 6.08 do not support flow control on the serial sensor port. It is recommended that the logger
firmware be upgraded to the latest available release.
Every command seems to generate an error message
This may occur if you fail to send the
END
command following an earlier
BEGIN
. All commands other than numbered
slot definition commands are invalid when inside a BEGIN-END block. Send an
END
command to restore proper
operation.
SNOOP returns no data
Verify that the ECU is correctly wired to the CAN port you specified in the
SNOOP
command
Ensure that the bit rate has been set for the CAN port in use, using the
CONNECT
command
Verify that the ECU is powered correctly. If you are talking to a single ECU on the bench then it may require one or
more connector pins to be linked to indicate to it that the ignition switch is on.
Check the LED for the CAN port. It should flash while the snoop is active as messages are received. (If the other CAN
port is connected to an active bus then its LED may also flash during the snoop.)
If the CAN LED gives a brief flash at two second intervals then this may indicate that bus errors are occurring, causing
CANgate to disconnect from the bus then retry every 2 seconds. Switch on Verbose mode to see whether bus error
messages are being returned. If so, refer to the Bus Errors section above.
Broadcast CAN data are not returned
In other words you have defined a RECV, RECVE or RECVJ memory slot but nothing is returned when it is polled
Use
the
STATUS
command to verify that the slot definition has been accepted by CANgate. Remember that in
non-verbose mode no error messages are issued. If some slots don't appear in the status display or don't look right,
switch on Verbose mode and send the slot definition(s) again to see if any error messages are reported.
Double check all of the memory slot definition parameters, especially ECU address and priority (for RECVJ). Note that
a given ECU will generally only implement a subset of the possible set of PGNs/PIDs.
Is the specified CAN ID or PGN being broadcast by the ECU? Use the
SNOOP
or
SNOOPJ
command to verify this. If
the ID/PGN doesn't appear in the snoop list then it's not being broadcast. Note that for infrequently broadcast
parameters you may need to extend the snoop time (eg.
SNOOP 1 60000
to have CANgate listen for messages for
60 seconds)
It is possible that at the time the slot was polled, no data had yet been received. Note that the
RP
command should not
be appended to the end of a RECV/RECVE/RECVJ slot definition, because at that time it is almost certain that no
messages will have been received in the time since the definition command was processed.
Check the CAN LED. Once the memory slot has been set up, the LED should flash when matching messages are
received. Note that if any J1939 slots are defined, the LED will flash on receipt of any multi-packet message. (Non
matching multi-packet messages will be discarded by the CANgate firmware.)
Only
one memory slot can reliably receive a data field longer than 8 bytes from a multi-packet J1939 broadcast. If you
define two or more slots which return more than 8 bytes of data then they may sometimes return no data, depending
on the timing of the broadcast messages. If you need to receive data from multiple multi-packet PGNs then multiple
slots should be used, each configured to return no more than 8 bytes.
When receiving multi-packet messages using RECVJ, check that the specified start/end byte positions don't extend
past the actual size of the message – if they do then no data will be returned. The value 0 can be used as the endByte
parameter (in fact it is the default), which means the last byte received for a particular message.
