Omron NT-series Programmable Terminal V022-E3-1 User Manual

Page 179

. 3

Section 5-2

Direct specification

Direct specification is a method of specification in which the contents of dis-
played memory tables are directly correlated with the contents of the allocated
words.

NT600S

Character string
memory table 51

Allocated channel
(character string memory table 51)

Direct
specification

Indirect specification (with Ver.5 direct connection only)

In indirect specification, even if the displayed data is a character string, the dis-
play is correlated with a numeral memory table. The contents (numerical value)
of this numeral memory table are regarded as a character string memory table
number and the contents of the table with this number are displayed.
Up to 50 numeral displays and 50 character string displays can be specified on
one screen by using indirect specification.

NT600S

Numeral
memory table 20

Character
string memory table 51

Allocated word (numeral memory table 20)

Allocated word (character string table 51)

Indirect
specification

This specification method is a little complex, but it allows the display to be changed
more easily according to the circumstances. In the example above, if 1 were add-
ed to the contents of memory table 20 to give 52, the contents of memory table 52
would be displayed instead.
The memory tables used for display can also be allocated to areas in the PC, so
that the display can also be changed in response to changes in the data to be dis-
played (i.e., the contents of character string memory table 51 in the example
above).
However, in comparison with direct specification, indirect specification requires
more time for processing.

Setting the Words of the Character-String Memory Table

When creating the screen data by using the support tool, make the following set-
tings for each numbered character-string:

Initialization setting

Set whether or not the PC words are initialized with the character-string memory
table initial value registered to the screen data memory when the main power
supply is turned ON or reset.