B&B Electronics GW-7433D - Manual - Manual (Page 24)

3.5 SJA1000 CAN Status
Users can use the Modbus command to get the CAN status of the
SJA1000 CAN controller which is applied in GW-7433D. The meaning of each
bit of the CAN status is as follow table 3-1. About how to get the CAN status
please refer to the section 4.2.2 (Special Data Addressing).
Bit Name Value Function
1
bus-off ; the SJA1000 is not allowed to access the CANopen
network Bit. 7
Bus Status
0 bus-on ; the SJA1000 is ready to access the CANopen network.
1
error ; at least one of the error counters has reached or exceeded
the CPU warning limit Bit. 6
Error Status
0
ok ; both error counters are under the warning limit
1 transmit ; the SJA1000 is transmitting a message
Bit. 5
Transmit Status
0
idle ; no transmit message is in progress
1
receive ; the SJA1000 is receiving a message
Bit. 4
Receive Status
0 idle ; no receive message is in progress
1
complete ; the last requested transmission has been successfully
completed
Bit. 3
Transmission
Complete Status
0
incomplete ; the previously requested transmission is not yet
completed
1 released ; the CPU may write a message into the transmit buffer
Bit. 2
Transmit Buffer
Status
0
locked ; the CPU cannot access the transmit buffer; a message is
waiting for transmission or is already in process
1
overrun ; a message was lost because there was not enough
space for that message in the RXFIFO
Bit. 1
Data Overrun
Status
0
absent ; no data overrun has occurred since the last clear data
overrun command was given
1 full ; one or more messages are available in the RXFIFO
Bit. 0
Receive Buffer
Status 0 empty ; no message is available
Table 3-1 Bit interpretation of the CAN status
GW-7433D MODBUS TCP/RTU to CANopen Gateway User Manual 24
(Version 2.0.0, Jul/2011)