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Using Socket Services with CMND(490) Section 6-3
6-3 Using Socket Services with CMND(490)
Service request commands can be sent to the Ethernet Unit by executing the
CMND(490) instruction in the ladder diagram. CS/CJ Ethernet Units support
the same functionality as the CV-series Ethernet Unit, so heritage programs
can be easily corrected and reused.
Up to 16 sockets can be connected using CMND(490): 8 UDP sockets and
8 TCP sockets.
The socket service request commands that can be used are listed in the fol-
lowing table. Refer to Section 11 FINS Commands Addressed to Ethernet
Units for details on these commands.
Requests sent to the Ethernet Unit by sending commands through execution
of CMND(40), and when the Unit receives a command, it will return a
response. The response does not, however, indicate that processing has
been completed, and the status of the flags in the Socket Status Words allo-
cated to the Unit must be used to determine when processing has been com-
pleted.
The results of processing will be stored in the words specified when
CMND(490) was executed once the requested processing has been com-
pleted.
Basic FINS Command
Format
The basic format for FINS commands used for socket services is shown in the
following diagram.
Command Code:
Specifies the process code requested from the socket.
Socket Number
Specifies the socket number for the process, between 1 and 8.
Results Storage Area
Specifies the area to store the results of the requested process.
Parameters
Specifies the parameters defined for the command code.
Command code Name
MRC SRC
27 01 UDP OPEN REQUEST
02 UDP RECEIVE REQUEST
03 UDP SEND REQUEST
04 UDP CLOSE REQUEST
10 TCP PASSIVE OPEN REQUEST
11 TCP ACTIVE OPEN REQUEST
12 TCP RECEIVE REQUEST
13 TCP SEND REQUEST
14 TCP CLOSE REQUEST
Socket
number
0123456789101112
Command
code
Results storage area Parameters
Byte order from
the beginning of
the frame