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Using Socket Services with CMND(490) Section 6-8
6-8-9 UDP/IP Communications Programming Example
The following programming example illustrates transferring 100 bytes of data
between an Ethernet Unit and a host computer using UDP/IP
communications.
For the UDP connection, the Ethernet Unit uses a PASSIVE OPEN and the
host computer uses an ACTIVE OPEN.
System Configuration
The system configuration for the program example and the Ethernet Unit
system setup are shown below.
Basic Operations
• CIO 000000 is turned ON to request opening a UDP socket from the
Ethernet Unit.
• CIO 000001 is turned ON to request closing the UDP socket from the
Ethernet Unit.
• CIO 000002 is turned ON to request sending data from the Ethernet Unit.
Data (100 bytes) is sent beginning at D02008.
• CIO 000003 is turned ON to request receiving data from the Ethernet
Unit. The data that is received (100 bytes) is stored beginning at D04025.
• One of the bits between CIO 000100 and CIO 000103 will turn ON if an
error occurs. Refer to 6-7-5 Socket Service Request Switches for informa-
tion on errors. The following areas can be used to access details about
errors:
CMND(490) response codes
Response codes in results storage area
Network Communications Error Flags (A21900 to A21907)
Completion codes (A203 to A210)
Host computer
Ethernet Unit
IP address: 196.36.32.55
Port number: 4096
IP address: 196.36.32.101
Port number: 4096
FINS network address: 01 Hex
Node address: 01 Hex
Unit number: 10 Hex
PLC