Omron NT21 - SETUP MANUAL 10-2001 Setup Manual page 186

Troubleshooting
NT21 Symptoms
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 NT
Support Tool. pp
Updating of numeric
values and text is a ues a d te t s
delayed.
Some of the elements
arranged on a normal a a ged o a o a
screen are not displayed.
On overlapping screens,
some of the set elements
are not displayed.
The System Menu cannot
be called up.
Cause
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.
An optional battery was installed, but
the battery has weakened and the
data in the memory table has been
lost.
An optional battery was installed and
the resume function is set to ON, so
the initial values set with the NT
Support Tool are not reflected in the
memory tables.
The numeral memory table is
specified as the destination for a
mathematical table results.
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
screens has exceeded the maximum
permissible without being checked
by the NT Support Tool.
Display System Menu under Change
System Settings in the System
Installer mode is set to Disabled.
Remedy
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 as follows when
using the Programming Console function.
S With C-series PLC: 1:1 NT Link
S With CS/CJ-series PLC:
1:N NT Link (standard or high-speed)
The Programming Console and the Programming
Console function can be used at the same time in
CS/CJ series PCs only. If another model of PC is
being used, 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 165)
When the contents of the memory table are set as a
fixed values, do not allocate the memory table to the
host memory.
Replace the battery and initialize the memory table.
(7-3-1 Installing or Replacing the Battery, page 184,
and 6-4-4 Initializing the Memory Tables, page 114)
Execute memory table initialization. (6-4-4
Initializing the Memory Tables, page 114)
If the resume function does not need to be used, set
the NT21 with the resume function OFF. (6-9-8
Setting the Resume Function, page 140)
Calculations are executed continuously while the PT
is operating and the calculation results are
automatically written to the memory table. Specify
another numeral memory table entry or a word in
the host.
Carry out grounding work in accordance with the
conditions by referring to 3-1-4 Grounding, page 18.
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 in Appendix A of the e e g to sp ay est ct o s
Reference Manual. Create the screen data again f C
and then transmit all of the screen data in a batch to
the NT21.
Check the maximum number of elements by
referring to Display Restrictions in Appendix A of the
Reference Manual. Create the screen data again
and then send all the screen data in a batch to the
NT21.
In the System Installer mode, set Display System
Menu to Enabled (page 121).
Section 7-1
ppe d o t e
175