2-16SectionSpecial Functions
249
Frequency Order Screen
Cycle time over 114
Abnormal high function unit 153
Abnormal remote I/O 139
The following countermeasure should
be taken:Program is checked again.
Setting of cycle time over not detected
(DM6655:X1XX)
Cycle time exceeds
100 msec!
2-16-3 Resume Function
The PT has a function to protect the contents of memory table entries that have
been changed during operation (by the numeral/character string setting func-
tion, or by an instruction from the host) and retain them even when the power to
the PT is OFF or the PT is reset, so that operation can be restarted in the same
status the next time the PT is started. This function is called the resume function.
When the resume function is not set, the contents of the memory table entries
are initialized to the defaults (initial values) set with the Support Tool when PT
operation has been stopped by turning OFF the power, resetting the PT, or stop-
ping operation from the System Menu.
When the resume function is set, the contents of the memory table entries are
not initialized when PT operation has been stopped by turning OFF the power,
resetting the PT, or stopping operation from the System Menu. This means that
the next time that operation is restarted, the data previously contained in the
memory table entries will be written to the host automatically so the same data
can be displayed again at the host after an interruption.
The resume function will retain data in numeral memory table entries 0 to 999
and character string memory table entries 0 to 499. All other memory table en-
tries will be initialized, whether the resume function is set or not.
However, when a word is allocated for a memory table entry in the host and the
memory table entry is set not to be initialized, the contents of the word at the host
will be written to the memory table entry instead of the other way round, therefore
the previous contents of the memory table entry will be lost.
Even if the resume function is set, if memory table initialization is executed, the
memory table contents will be initialized to the defaults set with the Support Tool.
Whether the resume function is used or not is set with the memory switches of
the PT. For details, refer to section 6 of the Setup Manual.
Reference: When the voltage of the battery becomes too low, the memory table contents
cannot be retained even if ON is set for the resume function. The Battery is an
option for the NT21, and the resume function will be disabled if a Battery is not
being used, regardless of the actually setting of the function.
2-16-4 Screen Saver Function
The PT has a function to maximize the service life of the backlight and to prevent
the formation of an afterimage by turning off the screen display and the backlight
if no operation is performed for a certain period of time.
If the same data is displayed for a long time (about 24 hours), an afterimage will
form on the screen. To prevent this, either use the screen saver function or peri-
odically switch the screen.
The screen saver function only operates when the PT is in operation. It does not
operate during System Menu operation or while the PT is in system installer
mode.