Specifications

2 - 5
(3) External devices capable of exchanging data
The communication using the MC protocol can be performed from the following
external devices.
1) External devices that are connected to the same Ethernet as the Ethernet
module
2) External devices that are connected to other Ethernet networks via routers
3) External devices that are connected to the MELSECNET/H via PLC CPUs
Ethernet-2
Ethernet-1
Personal computer
Personal computer
Personal computer
Personal computer
Router
PLC CPU
PLC CPU
(Access
target station)
MELSECNET/H
2)
1)
3)
(4) Outline of data sending/receiving procedures
Data are sent/received as shown below.
(a) TCP/IP communication
Device
memory
Ethernet module
Receiving command
Sending ACK
Receiving ACK
Send
processing
Receive
processing
Sending response
External device
PLC CPU
(b) UDP/IP communication
Ethernet module
Receiving command
Sending response
External device
PLC CPU
Device
memory
Send
processing
Receive
processing
REMARK
Refer to the Q Corresponding Ethernet Interface Module User's Manual (Basic) for a
communication program example on the personal computer side when using the
following languages for communication using the MC protocol.
• Microsoft
R
Corporation Visual C++
• Microsoft
R
Corporation visual basic