6-11
Section
System Maintenance
147
6-11 System Maintenance
The NT21 has the following maintenance and check functions.
Item
Function
Page
Calendar Check
Displays the last time data read from the host.
Page 147
PT Settings
Direct connection setting of the screen data in the NT21 and displays of the setting
statuses of the serial ports.
Page 149
Display history record
Displays display history record data.
Page 150
Alarm history record
Displays alarm history record data.
Page 151
Screen data check
Displays of each screen stored in the NT21.
Page 153
I/O
Device check Checks the I/O functions of the NT21.
Page 156
I/O
check
I/F check
Checks the communication functions of the NT21.
Page 161
This section describes how to use these functions.
6-11-1 Displaying/Setting the Calendar and Clock
The NT21 has a clock function that displays the date and time.
When the NT21 is in RUN mode, it regularly reads the clock data from the speci-
fied area in the host and stores that data in numeral memory table entries 247 to
253. The “Calendar Check” displays the most recent clock data read from the
host.
Reference:
S
The NT21’s clock function is not a counter. This function just displays the most
recent clock data read from the host.
S
The clock data is initialized to the default settings when the NT21 is turned OFF.
The default date and time is 01/01/00 00:00:00. (The clock data is not backed
up even if a battery is installed.)
S
After the NT21 is turned ON, the default date and time (01/01/00 00:00:00) will
be displayed until communications are established with the host and the clock
data is read properly from the host.
S
The clock function does not strictly check the date and day of the week settings.
S
The clock data cannot be set from the NT21’s System Menu or the NT Support
Tool.
S
Numeral memory table entries 247 to 253 are reserved for the clock function
(read-only). Clock data can be read from these addresses in the numeral
memory table during operation and displayed.