D Nt30/30C Internal Processing - Omron NT30 Operation Manual

The following processing is executed inside the NT30/30C. Processing is divided into two types: periodic proces-
sing and event processing.
Periodic Processing
The following processing is executed inside the NT30/30C to enable high-speed control from the PC.
Usually, the only data read from the PC are the elements used for the currently displayed screen. Even if the con-
tents of the PC words allocated to memory tables are changed, these contents are not updated at the PT unless
the memory table is used for the displayed screen. However, the bit memory table that can be used with Ver.3 and
later versions of the direct connection function can be set to be read continually.
NT30/30C (PT) Processing
PT power ON
Initial processing
Operation start
Initial values written to the memory tables
Screen switching
Screen element registration
Reading of registered elements
Reading of of the elements that could not be
registered
Reading of of the elements that could not be
registered
Reading of the PT status control area
Reading of of the elements that could not be
registered
Reading of of the elements that could not be
registered
Reading of the PT status control area
Appendix D
NT30/30C Internal Processing
(PT→PC)
(PT→PC)
(PT←PC)
(PT←PC)
(PT←PC)
(PT←PC)
(PT←PC)
(PT←PC)
(PT←PC)
Details of Processing
Hardware check, communication status check, etc.,
executed
When the values registered in the NT30/30C are used
as the initial values in the memory tables, these values
are written into the allocated words of the PC.
In order to enable fast batch processing, the elements
used in the displayed screen are registered in the PC
in advance. Approximately 120 words can be
registered per screen.
The statuses of the registered elements are read from
the PC and the display is changed.
The status of the elements that were in excess of the
number that could be registered is read from the PC,
and the display is changed. This processing is
continued until the statuses of all the remaining
elements has been read.
If the number of elements that could not be registered is
large, the PT status control area is read after every two
element readings.
: Processing performed if necessary
267