GT10/GT30

7.1 Switching Screens

 

 

Contents of basic communication area / word device

Screen switching

Screen No. 1

instruction

First word (screen no. instruction from PLC)

1

Currently display

Third word (currently displayed screen no.)

screen number changes

1

Screen is switched in response to function switch parts (Change Screen operation mode)

Change is not reflected

First word (screen no. instruction from PLC)

Screen No. 2

 

 

Currently displayed

 

Third word (currently displayed screen no.)

screen no. is changed

 

 

1

2

Screen changing instruction from PLC

 

Screen changing

 

 

 

Screen No. 2

First word (screen no. instruction from PLC)

 

1

instruction

 

 

 

 

 

 

 

 

 

 

 

In this state, “1” is already written for the first word, so if an instruction is sent from the PLC to the first word to display Screen No. 1, it duplicates what is already written, and the screen will not be switched.

This problem can be solved in the following manner:

Use the “forced–display flag” in the basic communication area/bit device.

1)At the same time that the PLC issues an instruction to change the screen again to Screen No. 1, or shortly after that point, the forced–display flag in the first word/Bit E of the basic communication area/bit device is turned on, using the bit as a PLC bit operation instruction.

2)When the forced–display flag begins to go on, the screen corresponding to the number written to the first word of the basic communication area/word device, meaning Screen No. 1, is forcibly displayed at the point that step 1 takes place. (This is carried out only at the rise of the forced–display flag).

3)After the screen has been switched, the forced–display flag should be turned off.

Set the operation mode of the function switch parts to “Value Set”. When the screen is switched using the function switch parts, as shown in the illustration above, the operation mode of the function switch parts is set to “Value Set” in order to switch the screen. (For detailed information, see page 117.)

Using the “Value Set” mode changes the contents of the first word in the basic communication area/word device (the screen number specified by the PLC) and the third word (the number of the

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