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I-7540D CAN-Ethernet Gateway User’s Manual (Version 1.8, March/2021)
64
Table 4-4: CAN status register list
AsciiToHex(
FF
)
Name
Value
Function
Bit 7 (MSB)
Bus Status
1
Bus-off; the SJA100 is not involved in bus
activities
0
Bus-on; the SJA1000 is involved in bus
activities
Bit 6
Error Status
1
Error; at least one of the error counter has
reached or exceeded the CPU warning
limit
0
Ok; both error counters are below the
warning limit
Bit 5
Transmit Status
1
Transmit; the SJA1000 is transmitting a
message
0
Idle; no transmit message is in progress
Bit 4
Receive Status
1
Receive; the SJA1000 is receiving a
message
0
Idle; no receive message is in progress
Bit 3
Transmission
Complete Status
1
Complete; the previously requested
transmission is not yet completed
0
Incomplete; the previously requested
transmission is not yet complement
Bit 2
Transmit Buffer
Status
1
Released; the CPU may write a message
into the transmit buffer
0
Locked; a message is waiting for
transmission or is already in process
Bit 1
Data Overrun Status
1
Overrun; a message was lost
0
Absent; no data overrun has occurred
Bit 0 (LSB)
Receive Buffer Status
1
Full; one or more messages are available
in the RXFIFO
0
Empty; no message is available
Table 4-5: CAN Error flag list
AsciiToHex(
O
)
Description
Bit 3 =1
CAN Transmit Error
Bit 2 = 1
CAN Receive Error
Bit 1 =1
CAN FIFO Overflow
Bit 0 =1
Initial CAN Chip Error
Example:
Command (
ASCII
): 99S
Command (
HEX
): 39 39 53
Receive: !40C00000<CR>
Obtain some current information on the I-7540D module. The response will
show the following results: CAN baud rate=125K, CAN status register=
transmission complete and transmit buffer is released, CAN transmit error
counter=0, CAN receive error counter=0 and CAN FIFO= normal.
Note:
This command can only be accepted by 7540D’s port
10000