CAN Master/Slave
Kendrion Kuhnke Automation GmbH
430
17 May 2021
Input Data (IO -> PLC, 0..160 Bytes)
Name
Size
Source
StateData
8 bytes
IO
RxData1[0..7]
8 bytes
IO
…
…
…
RxData19[0..7]
8 bytes
IO
StateData:
Name
Format
Source
TxCounterCon
Word
The gateway shows the TxCounter again to confirm the new out-
queue data.
RxCounter
Word
Incrementing the RxCounter indicates that the process image
contains new in-queue data.
RxNrOfMsg
Word
Number of CAN messages in the process image. Range: 0..9.
ResetErrorAck
Bit (1)
Acknowledges the state of the Reset Error signal.
EtherCATError
Bit (1)
If 1: Sync Manager watchdog triggered (watchdog control)
CanTxQueueOvr
Bit (1)
Overflow of the gateway's out-buffer. Too much CAN data is being
sent or CAN bus the baud rate is too low.
CanRxQueueOvr
Bit (1)
In-buffer overflow. CAN data is being accepted too slowly. Either
speed up the EtherCAT task or reduce the bus load.
TxCounterMiss
Bit(1)
The gateway checks the TxCounter for steady increments. This
error indicates a skipped increment.
Best use TxCounterCon to send new data.
CanWarning
Bit (1)
Indicates the CAN controller states "CAN Warning" and "Error
Passive". These states are retained unless several frames are
sent and received without errors.
Reset Error is NOT required to acknowledge the bit.
CanBusOff
Bit(1)
Massive problems have changed the CAN controller's state to
"bus off". The controller will quit this error state automatically.
Unused 0..5
Bit (6)
CanTxBusy
Bit(1)
1: Data is being sent.
Unused 6..7
Bit (2)
RxData1,2 / 3,4 / 5,6 / 7,8 / 9,10 / 11,12 / 13,14 / 15,16 / 17,18 :
Byte
Name
Explanation
0
CanIdLowWordLowByte
CAN Identifier.
ExtendedId = 0 -> 11 bit.
ExtendedId = 1 -> 29 bit.
1
CanIdLowWordHighByte
2
CanIdHighWordLowByte
3
CanIdHighWordHighByte
4
CanDataLength
Number of data bytes. Range: 0..8
5
RemoteFrame
RemoteFrame = 1 -> no data, just request to send the identifier
6
ExtendendId
ExtendedId = 0 -> 11 bit, ExtendedId = 1 -> 29 bit.
7
Reserved
-
8
Data[0]
Payload data.
Only the number of bytes in “CanDataLength” is accepted.
9
Data[1]
10
Data[2]
11
Data[3]
12
Data[4]
