GT10/GT30

3.4 Setting the Basic Communication Area, GT30 and PLC

 

 

3.4Setting the Basic Communication Area, GT30 and PLC

3.4.1What is the Basic Communication Area?

Communication between the GT30 and PLC is carried out as shown below.

Ongoing

Communication

GT30

Basic communication area

For screen switching settings and system control

(word device / bit device: 3 words each)

Part reference / output device

For part functions

(free device specification)

PLC

Internal PLC devices

As shown in the illustration, communication is carried out on an ongoing basis between the GT30 and internal devices in the PLC. Internal PLC devices are divided into the following two devices:

Basic communication area

This area is for system control, such as screen switching settings. PLC devices belong to this area on a fixed basis, and communication is constantly being carried out.

Breakdown of the basic communication area

Word devices (DT, FL, etc.)

 

Bit devices (WR, etc.)

 

 

 

 

 

 

 

 

 

 

3 consecutive words

 

3 consecutive words

 

 

 

 

 

 

 

 

 

 

–Word devices ––– For reading devices handled in word units (3 consecutive words)

–Bit devices ––– For reading devices handled in bit units (3 consecutive words)

References and output devices for parts

These are devices that are used in parts functions, and can be freely specified by the user. Communication is carried out on an ongoing basis only for those that are currently displayed on the screen and pertain to devices currently in use.

With the GT30, before GTWIN screen creation tool is used to specify the devices for parts functions, the “basic communication area” must be determined.

DT0 to DT2 and WR0 to WR2 are set as the default values for the basic communication area, but the initial address can be changed using the following procedure.

CAUTION

The basic communication area should be used in the PLC ladder program to control the GT main unit.

Settings in GTWIN

Select “Configuration” under “File” on the menu bar, and then select the sub–menu called “GT Configuration”. This displays the dialog box for the GT30 Basic Setup, as

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