JVL MAC050 User Manual page 198

5.6 Expansion Mod. MAC00-FC2/FC4/FC41
5.6.17 MacTalk CAN debug window
The hardware CAN Node chip have a Node Control Register, this controls the initiali-
zation, defines the node specific interrupt handling and selects an operation mode. The
Node Control Register have a field call LEC (Last Error Code), this bit field indicates if
the latest CAN message has been correct (No error) or it indicates the type of error,
which has been detected.
The register contains the following fields:
Bit
Field
Read
Write
Where:
Field
LEC
TXOK
RXOK
EWRN
BOFF
Table for last Error code
LEC
000
001
010
011
100
101
110
111
194
15-8 7
0 BOFF
X X
Meaning
Last Error Code
Message Transmit-
ted Successfully
Message Received
Successfully
Error Warning Status
Bus-Off Status
Meaning Description
No error The latest transfer on the CAN bus has been completed successfully
More than 5 equal bits in a sequence have occurred in a part of a received
Stuff error
message where this is not allowed
Form error A fixed format part of a received frame has the wrong format
Ack error The transmitted message was not acknowledged by another node
Bit1 error During a message transmission the CAN node tried to send a recessive level
(1), but the monitored bus value was dominant (outside the arbitration field
and the acknowledge slot)
Bit0 error Two different conditions are signaledby this code:
1. During transmission of a message (or acknowledge bit, active error flag,
overload flag), the CAN node tried to send a dominant level (0), but the mon-
itored bus value has been recessive.
2. During bus-off recovery, this code is set each time a sequence of 11 reces-
sive bits has been monitored. The CPU may use this code as an indication,
that the bus is not continuously disturbed
CRC error The CRC check sum of the received message was incorrect
Reserved
JVL A/S - User Manual - Integrated Servo Motors MAC050 - 4500
6 5 4
EWRN 0 RXOK
X X
X
Value Description
See table below
0 No successful transmission since last flag reset
1 A message has been transmitted successfully (error free
and acknowledged by at least one other node)
0 No successful reception since last flag reset.
1 A message has been received successfully.
0 No warning limit exceeded.
1 One of the error counters in the Error Management Logic
reached the error warning limit of 96
0 CAN controller is not in the bus-off state.
1 CAN controller is in the bus-off state
3 2 1
TXOK LEC
X X
X X
0