Omron CS/CJ Series Network Card User Manual


 
19
Socket Services Section 2-3
CMND(490) instructions in the ladder-diagram program. This enables control
operations such as the reading and writing of I/O memory between PCs,
mode changes, and file memory operations. (When a FINS message is sent
on an Ethernet network, a UDP/IP header is automatically added to the mes-
sage.)
The FINS gateway function allows access not only to PCs on the same Ether-
net network, but also to PCs on other networks such as SYSMAC LINK or
Controller Link.
Executing from the host computer FINS commands with UDP/IP headers
added enables various control operations such as the reading and writing of
I/O memory of PCs on the Ethernet network, mode changes, and file memory
operations.
2-3 Socket Services
The socket services allow devices on the Ethernet to send and receive vari-
ous data using the UDP or TCP protocol. There are two ways to use socket
services, as explained below. (For details, refer to Section 6 Socket Services.)
By Manipulating
Dedicated Control
Switches
The first way to use socket services is to set the required parameters in the
parameter area allocated in the DM Area, and then to request particular UDP
or TCP socket services by turning ON dedicated control switches in memory.
The Ethernet Unit turns OFF the same bit when the requested process has
been completed. Data that is sent or received is automatically handled
according to the I/O memory locations specified in the parameter area.
Ethernet
CS/CJ-series
CPU Unit
Ethernet Unit
User program
SEND(090,
RECV(098), or
CMND(490)
Ethernet Unit Ethernet Unit
Ethernet
CS/CJ-series
CPU Unit
Ethernet Unit