An Overview Of The Data Transfer Function; What Is The Data Transfer Function - Panasonic FP2 ET-LAN Technical Manual

8.1 An Overview of the Data Transfer Function

8.1.1 What is the Data Transfer Function?

With the data transfer function in the ET-LAN unit, program instructions (the SEND and RECV
instructions) in the programmable controller are used to transfer data. Data can be transferred between
the units indicated below.
- Between open PLC and another
- Between a PLC and computer
The maximum amount of data that can be transferred with a single data transfer instructions is 1020
words.
SEND instruction
RECV instruction
Note:
When using the data transfer function, TCP/IP should be used in order to assure the reliability of the
communication.
Key Point:
With data transfer, the programmable controller specifies an IP address and a MEWTOCOL station
-
number (1 to 64), and opens a connection with the computer (partner node) in the MEWTOCOL
communication mode.
After the connection has been opened, the communication destination is specified only by the
-
MEWTOCOL station number (1 to 64) in the ladder program on the programmable controller side.
Data transfer enables up to eight simultaneous connections, in conjunction with other communication
-
functions, using a single ET-LAN unit.
There is no need to notate a program to handle communication, after the connection has been opened,
-
for the programmable controller on the side that receives the data transfer command.
The computer link function and data transmission function can be run on the same connection at the
-
same time.
8-2
Writes data to the I/O or register of the partner node
Reads data from the I/O or register of the partner node