Manual

Interface Functions 48
Doc.Id. HMSI-216-117
CM CANopen Module for SIMATIC S7-1200
Doc.Rev. 1.00
8.2 Transparent CAN Interface Functions
There are separate function blocks handling the transparent CAN functionality. These are available for
download from www.hms-networks.com/can-for-S7-1200. The functionality is described in
“Transpar-
ent CAN Mode” on page 6.
CAN_SEND and CAN_RCV handle the frames that are sent or received and CAN_CTRL controls the
state and the settings of the CAN layer. The transparent mode is turned on by choosing “Transparent
CAN” as operating mode during configuration in TIA Portal.
Get Diagnostic Information is used to read diagnostic information from the CM CANopen module to
the PLC.
8.2.1 CAN_SEND
Input Parameters
Output Parameters
Description
When REQ turns TRUE, a CAN frame is sent according to the parameters defined by the user. When
the frame has been transferred to the module, BUSY will go FALSE, and a new frame can be sent.
Name Data type Description
REQ Bool Starts the block. Has to be set to TRUE for one scan cycle. Transmissions will occur
until REQ is set to false.
ID Word Logical address of the CM CANopen module.
RTR Bool RTR bit of the CAN frame to send.
COBID Word CAN ID on the CAN net
DB Dint Data to be sent on the CAN net
DATASIZE Uint Size of the data to be sent on the CAN net
ABORT Bool Aborts the current transmission when set to TRUE.
Name Data type Description
BUSY Bool If the function block needs more than one scan cycle, to send the frame, this output
is set to TRUE. It stays TRUE until the function block is done, when it is cleared to
FALSE.
RET Uint Error code, see “Error Codes (RET)” on page 59. Valid once the BUSY signal turns
FALSE until the next time the function block is started, i.e. when REQ is set to
TRUE.