Lenze ETC Motion Control - Manual (Page 412)

PLC programming
Library
CAN functions (only ETCxM)
8
8.8
8.8.6
l
412 EDSTCXN EN 2.0
8.8.6.5 ClearCanMsg (only ETCxM)
FUNCTION ClearCanMsg: BOOL
VAR_INPUT
handle_pr : DINT; (* Handle on the management structure *)
END_VAR
FUNCTION
This function can be used to delete the reception FIFO (see function
DefineCanMsg()). The return value of the function is of no consequence.
handle_pr : DINT;
handle_pr = DefineCanMsg(1, 1014, 1114, 32);
ClearCanMsg(handle_pr);
8.8.6.6 ReadCanMsg (only ETCxM)
FUNCTION ReadCanMsg: INT
VAR_INPUT
handle_pr : DINT; (* Handle on the management structure *)
dest_pr : DINT; (* Address to the data structure *)
END_VAR
With this function a CAN message can be read from the reception buffer. The
reception buffer is implemented as FIFO. The structure for reception data is
as follows:
TYPE CAN_MSG_TR
STRUCT
cobid_w : WORD;
size_b : BYTE;
rtr_bit : BOOL;
data_ab : ARRAY [0..7] OF BYTE;
END_STRUCT
END_TYPE
The variable dest_pr must always be given the address of a variable of type
CAN_MSG_TR (see example). This function will provide an immediate
return in any case. The meaning of the return values can be found in the
following table.
Return value Meaning
−2 Invalid handle
0 No new message in FIFO
1 New message available, no further message in FIFO
2 New message available and further messages in FIFO
Declaration
Description
Example
Declaration
Description