Omron NT20, User Manual

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Memory Tables and Bar Graphs Section 5-2
Since the AR area bits of the CVM1/CV series PLCs are allocated to the sys-
tem, they cannot be used for purposes other than the system use.
Note (1) LR 00000 to LR 00199 are converted to CIO 01000 to CIO 01199.
(2) The EM Area is supported only by the C200HX/HG/HE-(Z)E PLCs.
1,2,3... 1. Use the Support Tool to allocate the PT status control area (PLC to PT) to
the PLC memory.
2. Register the memory table entries for the numerals and character strings
to be displayed when creating the screen data by using the Support Tool.
To display a character string, use “character display” and specify the char-
acter-string memory table entry by using the Support Tool.
To display numerals, use “numeral display” and specify the numeral mem-
ory table entry by using the Support Tool.
3. Set the copy source data to the memory table entry when creating the
screen data by using the Support Tool.
Use “table edit”.
4. Create a PLC program to write the copy type, copy destination memory ta-
ble entry number, and copy source memory table entry number to the
“copy memory table entry” setting word in the PT status control area.
• Order for Writing to the PT Status Control Area (PLC to PT)
First write the “copy destination memory table entry number”, and then,
write the “copy source memory table entry number” to the PT status control
area (PLC to PT).
The NT20 reads the area sometimes when the PLC is writing the settings.
If the “copy source memory table entry number” has been written first and
is changed, unexpected memory table entries may possibly be changed.
• Allocated Words That the NT20 Reads
The NT20 reads the allocated words in the PLC for the memory table en-
tries which need to be displayed. Even when a copy source memory table
entry is allocated to a PLC word, if its contents are never displayed it will
be used only at initialization.
• Use of the Copy Type
Copy will not be executed when the “copy type” is other than “0” or “1”. The
memory table entry copy is executed only when the contents of the area
are changed. To repeat copying of the same copy source and same copy
destination, write a value other than “0” or “1” for the copy type, and then,
write a correct value again.
• Copying a Numeral Memory Table Entry
If the display method or the number of registered words include discrepan-
cies, a numeral memory table entry may not be copied and displayed cor-
rectly.
Application Example of Copying of a Character-String Memory Table Entry
This example gives a PLC program to switch the character string display on
the screen by using the memory table entry copy operation as the allocated
bit is turned ON and OFF.
• Support Tool Settings
Allocate the memory as shown below by using the Support Tool.
PT status control area allocation: Word 0100