LG GLOFA-GM Series, Руководство пользователя, Страница: 8 / 358

Chapter 1 Introduction
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Chapter 1 Introduction
This user’s manual describes Cnet (Computer network) I/F module of GLOFA PLC network system. Cnet is GLOFA
PLC network system using computer link module. Cnet has the connection function with different model to
communicate with communication devices of various different type protocols such as other company’s PLC and
computer, etc., and the function of modem communication to control remote PLC, and it has the following
characteristics.
Because communication speed and communication mode (protocol, etc.) are directly controlled by user using
program operative in Frame Editor of Windows environment, connection with other company’s products is easy.
Separate operations by channels are available through controlling each of other company’s protocol for channels
RS-232C and RS-422 (RS-485), and saving and using the protocol data controlled by user in internal flash
memory (128kbyte) are possible.
Variable reading/writing and program reading/writing are possible by using dedicated protocol.
Dedicated communication function suitable to multi-drop configuration connectable up to 32 units is provided.
With modem communication function built-in, remote PLC can be controlled by GMWIN connection, dedicated
communication, and user defined communication.
Communication port, RS-232C/RS-422 (RS-485) can be used by setting it to stand-alone or interlocking channel.
Various communication speeds can be set from 300bps to 76,800bps.
1:1/1:N/N:M communication (if RS-422 channel used) is available.
Communication types of full-duplex (RS-422/RS-232C) and half-duplex (RS-485) are supported.
Channel RS-422 can be used as multi-drop communication channel, RS-485 by basic parameter setting.
Modules can be mounted up to 8 units for GM1, GM2 and GM3, 4 units for GM4 and GM6, and 1 unit for GM7
(available only on the main base. And as linked with the basic module using an extended connector in case of
GM7.)
With satisfactory self-diagnosis function and Loop-Back diagnosis function, diagnosis of errors is easy to make.
With private functions of other products’ built-in, access is easy to such protocol as Modbus, A. B DF1. Ver.2.0