Omron NT31 Series, Operation Manuals

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Communication by Using Memory Link Section 1-4
1-4-2 Comparison between Direct Connection and Memory Link
The major differences between the direct connection and the memory link are as
follows:
a) In the memory link method, the communication with the host should be carried
out by using commands. Compared to the ordinal direct connection, which can
be used requiring almost no programs, the memory link method requires a
program that is necessary for interchange of commands.
This, however, gives advantages to the memory link method by using a large
variety of functions available in the direct connections from major models such
as a personal computer and a FA computer equipped with RS--232C/RS--422A
communication means, allowing the PT to be suited for larger usage.
b) Actual PCs have many kinds of areas, where as PT memory is a single area
with only one kind. When creating screen data by using the memory link
methods, it is always necessary to allocate display parts on the memory link
area.
For communication between the host and the PT by the memory linkmethod, refer
to “Section 9 Using Memory Link”, and for how to use screen and display elements,
refer to “Section 8 How to Use the PT”.