NAiS FP Series, User Manual

Page: 136 / 326

FP
Σ
7.1 Communication Functions of FP
Σ
7 - 3
7.1 Communication Functions of FP
Σ
This section explains about the communication functions of the optional communication
cassette.
7.1.1 Functions of Communication Cassette
There are three types of communication functions made possible by the FP
Σ
communication cassette, as described below.
Computer link
The computer link is used to carry out communication with a computer connected to the
PLC that has a transmission right. Instructions (command messages) are output to the
PLC, and the PLC responds (sends response messages) based on the received
instructions.
A MEWNET exclusive protocol called “MEWTOCOL-COM” is used to exchange data
between the computer and PLC. Two communication methods are available, 1:1 and
1:N. A network using the 1:N connection is called a C-NET.
The PLC sends back responses automatically in reply to commands from the computer,
so no program is necessary on the PLC side in order to carry out communication.
Computer
Command message
Response message
FP
Σ
Figure 127: FP
Σ
Computer link function
Applicable communication cassette
For 1:1 communication 1-channel RS232C type (Part No. FPG-COM1) . . . .
2-channel RS232C type (Part No. FPG-COM2)
For 1:N communication 1-channel RS485 type (Part No. FPG-COM3) . . .