Ethernet Units Operation Manual

113
Using Socket Services with Socket Service Request Switches Section 6-2
An illustration of using Socket Service Request Switches to execute socket
services is provided below.
Note 1. Socket Service Request Switches in the CPU Bus Unit 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.
After setting the required parameters in a Socket Service Parameter Area in
the CPU Bus Unit Area in the DM Area, the Socket Service Request Switches
can be used to request opening, sending, receiving, or closing for either the
UDP or TCP protocol. When requesting a send, send data at the send/receive
data addresses set in the parameter area is sent. When requesting a recep-
tion, data is received to the send/receive data addresses set in the parameter
area.
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
Sockets
Sockets