Specifications

2 - 10
(3) Outline of data sending/receiving procedures
Data are sent or received as shown in the following figures.
(a) TCP/IC communication
PLC CPU
TO instruction
FROM instruction
Ethernet module
(When writing)
(Data)
(Data)
Random access buffer
(When reading)
Receiving command
(Read/write request)
Sending ACK
Sending response
Receiving ACK
External device
Send
processing
Receive
processing
(b) UDP/IP communication
PLC CPU
TO instruction
FROM instruction
Ethernet module
(When writing)
(Data)
(Data)
Random access buffer
(When reading)
Receiving command
(Read/write request)
Sending response
External device
Send
processing
Receive
processing
2.2.4 Communicability with external devices for each data communication function
The Ethernet module has three types of communication functions: "Communication
using MC protocol", "Communication using fixed buffer" and "Communication using
random access buffer".
The following table shows the communicability with external devices for each
communication function of the Ethernet module.
External device (*1)
Function
Personal
computer
QJ71E71
Personal
computer
QJ71E71
QJ71E71
QJ71E71
QJ71E71
Conventional
model
Conventional
model
QJ71E71
Communication using
the MC protocol
Communication using
the fixed buffer
Communication using
the random access
buffer
: Available :N/A
*1 Conventional models represent Ethernet interface modules of MELSEC-A and
QnA series.