6-3
Section
Using Socket Services with CMND(490)
119
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. The CS1 Ethernet Unit supports
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 follow-
ing table. Refer to Section 11 FINS Commands Addressed to Ethernet Units for
details on these commands.
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
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 allocated to the Unit must
be used to determine when processing has been completed.
The results of processing will be stored in the words specified when CMND(490)
was executed once the requested processing has been completed.
The basic format for FINS commands used for socket services is shown in the
following diagram.
Socket
number
0
1
2
3
4
5
6
7
8
9
10
11
12
Command
code
Results storage area
Parameters
Byte order from
the beginning of
the frame
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.
Note If there is more than one Communications Unit mounted to the PC, the FINS net-
work address must be set as a parameter for CMND(490) and a local network
table must be created in the routing tables from the CX-Programmer.
Basic FINS Command
Format
