Omron NT631 Operation Manuals page 614

Troubleshooting
NT631/NT631C
Symptoms
The PC mode has
changed to the monitor
mode.
The graph display does
not change.
The trend graph display
does not agree with the
actual time axis.
The programming console
function cannot be used.
The memory table display
contents differ from the
initial value set at the
Support Tool.
Updating of numeric
values and text is values and text is
delayed.
Some of the elements
arranged on a normal arranged on a normal
screen are not displayed.
On an overlapping screen,
some of the set elements
are not displayed.
Cause
The NT631/NT631C changes the
mode when host link communication
is used.
One of the percentage display
settings — "−100%", "0%", or "100%"
— is incorrect.
The cycle for graph display update
processing is longer than the set
sampling cycle.
The communication settings are
incorrect.
A programming console is
connected.
The PC does not support the
programming console function.
Since the memory table is allocated
to the host memory, the display is
updated in accordance with the
contents of the host memory.
The battery voltage has dropped and
the data in the memory table has
been destroyed.
Since ON is set for the "resume
function", the initial values of the
screen data memory are not written
to the memory tables.
Malfunction due to external noise
There are too many numeral/text
displays on the displayed screen.
The cycle time is extended due to
heavy processing at the host.
In an RS–422A/485 connection,
there is illegal branching or an
erroneous terminator setting.
The quantity of read data exceeds
the stipulated restriction.
The total of the element coefficients
for the displayed screen is greater
than 1024.
Since the data is transmitted from the
host in screen units, the number of
elements on the overlapping screen
has exceeded the maximum
permissible without being checked
by the Support Tool.
Remedy
This is an NT631/NT631C specification. When using
a PC that can also be connected using the NT link
method, use an NT link connection (there is no mode
change with the NT link method).
Set the "−100%", "0%", and "100%" values in the
following relationship:
−100% value < 0% value < 100% value
Delete other elements on the same screen as the
trend graph that are allocated to the host and have a
high update frequency. Or lengthen the sampling
cycle.
Set the communication method/communication port
as follows when using the programming console
function.
- With C series PLC : NT Link : 1 : 1
- With CS1 series PLC : NT Link : 1 : N
It is not possible to use a programming console and
the programming console function at the same time.
Disconnect the programming console.
Not all PCs support the programming console
function. Check the model of PC you are using.
(6-12 "Programming Console Function", page 237)
When the contents of the memory table are set as a
fixed value, do not allocate the memory table to the
host.
Replace the battery and execute "memory table
initialization". (11-3-1 "Replacing the Battery", page
624, and 6-4-4 "Initializing the Memory Tables", page
161)
Execute "memory table initialization". (6-4-4
"Initializing the Memory Tables", page 161)
If the resume function does not need to be used, use
the NT631/NT631C with the resume function OFF.
(6-9-10 "Setting the Resume Function", page 199)
Carry out grounding work in accordance with the
conditions by referring to 3-1-4 "Grounding", page 40.
Reduce the number of numeral/text displays on the
screen for which updating is delayed.
Shorten the host cycle time.
Wire correctly by referring to Section 5 "Connecting to
the Host from the RS-422A/485 Port".
Check the maximum number of elements by referring
to "Display Restrictions" (page 635), create the screen to "Display Restrictions" (page 635), create the screen
data again, then transmit all of the screen data in a
batch to the NT631/NT631C.
Check the maximum number of elements by referring
to "Display Restrictions" (page 635), create the screen
data again, then send all the screen data in a batch to
the NT631/NT631C.
Section 11-1
609