Ethernet Units Operation Manual
135
Using Socket Services with Socket Service Request Switches Section 6-2
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.
• CIO 000003 is turned ON to request receiving data from the Ethernet
Unit. The data that is received (100 bytes) is stored beginning at D01000.
• One of the bits between CIO 000100 and CIO 000103 will turn ON if an
error occurs. Refer to6-2-2 Response Codes for information on errors.
Program Memory Map The send and receive data and bits (flags) used by the program are shown in
the following diagram.
DM Area
CIO Area
The following bits and flags are used to control CMND(490) execution. The
bits in CIO 0000 are used to signal execution, the bits in CIO 0001 are used to
signal errors, and the bits in CIO 0002 are used to control the program so that
the instruction is executed only once.
Send data, 100 bytes (100 = 0064 Hex)
Receive data, 100 bytes (100 = 0064 Hex)
76543210
CIO 0000
CIO 0001
15 to 8
CIO 0002
TCP 
Send 
Bit
TCP 
Close 
Bit
TCP 
Open 
Bit
TCP 
Receive 
Error 
Flag
TCP 
Send 
Error 
Flag
TCP 
Close 
Error 
Flag
TCP 
Open 
Error 
Flag
TCP 
Receiving 
Flag
TCP 
Sending 
Flag
TCP 
Closing 
Flag
TCP 
Opening 
Flag
TCP 
Receive 
Bit










