Doc.Id. SCM-1200-121
Anybus Communicator CAN to CANopen
Doc.Rev. 1.00
Chapter 10
10. Configuration of CAN Frames
10.1 General
Each transaction includes one or more CAN frames. A total of 256 CAN frames is allowed. Right-click-
ing on a transaction will give the opportunity to add a frame to the transaction.
The Anybus Configuration Manager makes it possible to decide the configuration of the 8 bytes of data
that can be included in each frame. The configuration manager automatically allocates memory space in
the input and output areas of the Communicator for the data objects that are configured in the frames.
The result can be seen in the Address Overview, see page 38. Any address conflicts will turn up red in
this view.
Note
: A CAN frame can not contain more than 8 bytes of data. It is possible to configure the data area
in each frame, but the size of the combination of objects must not exceed 8 bytes.
10.1.1 CAN Identifiers
Each frame has a CAN identifier, to make it possible for each node on the CAN network to recognize
data meant for it. Default identifier is ‘0’. It can be changed by selecting the CAN Frame and enter the
new CAN Identifier in the Parameter window.
The CAN frame has either a 11-bit identifier or a 29-bit identifier. If the size of the identifier is changed,
an 11-bit identifier will have the 11 original bits padded with zeroes in front. A 29 bit identifier will have
its 18 highest bits cut, which may cause a not valid 11-bit identifier.
It is possible to have several frames in one transaction. The first frame in a Consume or Response trans-
action must have a CAN identifier that does not appear in any other Consume or Response transaction.
Consecutive frames within a received transaction may have the same identifier, on two conditions:
• The first part of the data area in the frame is a byte, word or Dword constant with a unique value
compared to other frames with the same identifier within the transaction.
• If any frame with another identifier is added to the transaction, it must not break the sequence
of frames with identical identifiers.
