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1-4
Section
Communications with the Host
27
The PC bit allocated to bit memory table for which the history property has been
set is continually monitored: when the bit comes ON (1), the time and the number
of times, and the contents of the character string memory table registered for the
bit memory table, are recorded in the alarm history record data.
This record data can be displayed as the alarm history.
The PT status control area is used to control the PT status. When data is written
to this area in the PC, the PT reads the contents and operates according to the
contents.
Example of PT Status Control Area Application
When data is written to the PT status control area, the PT operates as shown
below (page 46).
PC
0003
0050
1007
A000
PT
Screen 3 display
Continuous
buzzer
sound
Numeral memory table 50
Copy
Numeral memory table 7
PT status control area
PT status control bits
Screen switch setting
Memory table
Copy setting
System reserve
The PT status notify area is used to notify the changes in the PT status.
When the PT status changes, the change is written to this area in the PC. By
reading the data from this area, the PT status can be checked.
Example of PT Status Notify Area Application
When the PT status changes, the change is applied to the PT status notify area
as shown below (page 55).
PC
12345678
1 2 3 4 5 6 7 8
5 6 7 8
1 2 3 4
12345678
8800
0013
PT
Numeral memory table 13
PT status notify area
Content upgrade memory table
PT status
Allocated word (numeral table 13)
Start
Start + 1
7 8 9
4 5 6
1 2 3
0 .
Reference:
When the PT is set to NT30/620 compatible mode, the word configuration is iden-
tical to that of the earlier NT30, NT30C, NT620S, NT620C, and NT625C PTs.
The window control area is used to notify and control the window status. The
window control area has areas that correspond to three windows. Each area
stores the screen number, and the X and Y coordinates of the lower left corner of
the window that is being displayed.
When data is written to this area in the PC, the PT reads the contents and exe-
cutes tasks such as switching the windows to be displayed or moving the posi-
tion of the windows according to the contents (page 232).
When the window display status changes, the change is written to this area in
the PC. By reading the data from this area, the window display status can be
checked (refer to page 232).
If the window functions are not used, it is not necessary to allocate a window con-
trol area to the host.
PT Status Control Area
(PC
↔
PT)
PT Status Notify Area
(PT to PC)
Functions of the Window
Control Area
(PC to and from PT)
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