Справочник Пользователя для Omron CS1W-ETN11

The socket services allow devices on the Ethernet to send and receive vari-
ous data using the UDP or TCP protocol. The socket services can be used by
CS/CJ-series PCs through the user program by manipulating dedicated bits
(called Socket Service Request Switches) or by executing the CMND(490)
instruction.

The two methods of using the socket services are as follows:

• Dedicated Bits (Socket Service Request Switches)

Requests can be made to a socket service by setting parameters and
then merely manipulating specific Socket Service Request Switches.

• CMND(490)

Requests can be made to a socket service by sending service request
commands to the Ethernet Unit.

Note One of the main differences between using Socket Service Request Switches

and using CMND(490) is in the number of sockets that can be connected
simultaneously, as shown in the following table.

1.

Socket Service Request Switches in the CPU Bus Area in the CIO Area
are used to send a service request from the CPU Unit to the Ethernet Unit.

2.

The Socket Service Parameters in the CPU Bus Unit Area in the DM Area
are used to specify the service being requested from the Ethernet Unit.
The CPU Bus Unit Area in the DM Area is also used to receive results of
processing from the Ethernet Unit to the CPU Unit.

UDP

Total of 8 sockets max.

8 sockets max.

TCP

8 sockets max.

CS/CJ-series PC

CPU Unit

Ethernet Unit

Socket Service 
Request Switches

Socket Service 
Parameters

Refreshed

(See note 1.)

Refreshed

(See note 2.)

TCP data 
transfers

UDP data 
transfers

Host computer 
or other device

System 
call

User program

Soc

k

ets

Soc

k

ets

CS/CJ-series PC

CPU Unit

Ethernet Unit

TCP data 
transfers

UDP data 
transfers

Host computer or other device

System 
call

User program

FINS 
command

FINS response

Processing 
results

Soc

k

ets

Soc

k

ets