Communication Fb Request Sequence - Toshiba V Series User Manual

5.5 Communication FB Request Sequence

Messages are sent and received to and from the S3CPU and the AN712 module using
FB (communication function block) by the sequence shown in figure 5-12 and figure 5-
13.
U S E N D _
U D P o p e n
U R C V _
S o c k e t P h - I D
a c q u i r e
U S E N D _
U D P s e n d r e q u e s t
( M e s s a g e d a t a )
U R C V _
U D P
r e q u e s t
The FB sequence for message transmission to other stations via the AN721 module is
based on a combination of communication function block instructions USEND_T and
URCV_T, and is posted to the AN712 module via socket interface processing by the S3.
Before sending a message, the sequence begins with creating a socket using the UDP
communication open function. The socket is a unit which can be parallel-processed. Up
to 12 sockets can be created per AN712 module (or per other communication module).
When a socket has been created normally, a message to the created socket (socket
number acquired) can be requested to the ADMAP-5M station. When message
transmission is completed, the application uses URCV_T instruction to receive a
response message to the request message, and thus obtains the result of normal
completion, or failure, of the request made by the application.
To receive a response message or a management/control message, check the socket
unit information (offset 0x7F80 and up) in the AN712 module for the receive data yes/no
flag (RCV) for each socket, and issue URCV_T instruction for receive request.
Note: To access socket unit information, it is necessary, after socket opening, to refer to
the socket numbers managed by the S3 controller, which may be obtained by
issuing URCV_T instruction to acquire the AN712 module management socket
identifier (16#001).
The application can receive the services of the AN712 module message transmission
function using the communication FB as described above.
6F8C1048
S 3 m o d u l e
A p p l i c a t i o n
S 3 s o c k e t p r o c e s s i n g
（ F B ）
r e c e i v e
Figure 5-12 Communication FB Request and Execution Sequence
(Message Transmission)
5.5Communication FB Request Sequence
A N 7 1 2 m o d u l e
E N _ S o c k e t ( )
E N _ S e n d T o ( )
E N _ R C V F r o m ( )
r a n s m i s s i o n
l i n e
M M S / L L C
R e q u e s t m e s s a g e
M M S / L L C
R e s p o n s e m e s s a g e
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