Communication via Function Blocks
6.3 Using the Function Blocks
Point-to-point connection CP 440 Installation and Parameter Assignment
98 Manual, 09/2007, A5E00057742-03
6.3.3 Deleting the Receive Buffer (11 "RES_RECV" FB)
The RES_RECV FB deletes the entire receive buffer of the CP 440. All the stored message
frames are discarded. A message frame coming in at the same time as the RES_RECV FB
call is saved.
The FB is activated by a positive edge at the REQ input. The job can run over several calls
(program cycles).
The FB RES_RECV function block can be called in the cycle when the signal state at the R
parameter input is "1". This terminates deletion and sets the RES_RECV FB back to its initial
state.
The LADDR parameter specifies the address of the CP 440 to be addressed.
Error Display on the RES_RECV FB
The DONE output shows "request completed without errors". ERROR indicates whether an
error has occurred. In STATUS the event number is displayed in the event of an error. If no
error occurs the value of STATUS is 0. DONE and ERROR/STATUS are also output in
response to a RESET of FB RES_RECV. In the event of an error, the binary result BR is
reset. If the block is terminated without errors, the binary result has the status "1".
Note
The RES_REC function block does not have a parameter check. If there are invalid
parameters, the CPU branches to STOP mode.
Table 6-6 Block call
STL representation LAD representation
CALL
RES_RECV, I_RES_RECV
REQ : =
LADDR: =
DONE : =
ERROR : =
STATUS : =
5(6B5(&9,B5(6B5(&9
(1
5(4
5
/$''5
(12
'21(
(5525
67$786
Note
The parameters EN and ENO are only present in the graphical representation (LAD or FBD).
The block is started with EN = TRUE. If the function is completed without errors, ENO =
TRUE is set. To process these parameters, the compiler uses the binary result BR. The
binary result is set to signal state "1" if the block was terminated without errors. If there was
an error, the BR is set to "0".
该文档是极速PDF编辑器生成，
如果想去掉该提示,请访问并下载：
http://www.jisupdfeditor.com/
To Next Page
Loading...
