Omron NT620S Operation Manual page 278

Hardware Faults
7-1 Hardware Faults
Caution
NT620S/620C Symptoms
POWER LED fails to
come ON
Nothing is displayed on
the screen (it is
completely white/LCD or
black/EL).
Communication with the
support tool not possible.
Cannot communicate with
the PC.
The buzzer sounds and
the RUN LED goes off.
Touch panel does not
react.
268
When a fault relating to the operation of the NT620S/620C occurs, find the symp-
toms in the table below and respond by following the corresponding "Remedy"
indicated in the table.
- Confirm system safety before turning the power ON/OFF or resetting. Other-
wise the system may operate unpredictably.
- Do not disassemble the NT620S/620C for repairs or modification. Otherwise,
the product may malfunction.
Cause
Power is not being supplied.
Power supply fuse has blown
Screen No. 0 has been read at the
PC side.
The Transmit Mode has not been
established.
Not connected to the support tool.
PT model setting and direct access
setting at the support tool do not
match the NT620/620C.
Memory switch settings do not
match.
NT620S/620C and PC are not
correctly connected.
In a host link connection, the PC
termination resistance setting is
incorrect.
In an NT link (1:N) connection, there
is duplication of unit numbers.
Incorrect operation due to external
noise.
Incorrect operation due to external
noise.
The touch panel is broken.
Remedy
Check the connections and make sure that power is
supplied correctly.
(Refer to 2-2-2 "Power Supply Connection", page
27.)
Contact your OMRON service center.
This is not an error. Change the screen number.
(Refer to 4-3 "Screen Display", page129.)
Display the system menu and select the Transmit
Mode.
(Refer to 3-6 "Registering the Screen Data", page
77.)
Check the installation of the connector cable.
(Refer to 2-3 "Connecting to the Support Tool", page
29.)
Using the "Tool Settings" of the support tool, set the
PT model and direct access settings that match the
NT620/620C.
Check the communication setting in the "Memory
Switch" menu of the Maintenance Mode, and match
the PC and NT620S/620C settings.
(Refer to 3-5 "Setting the Conditions of
Communications with the PC by Using the Memory
Switches", page 69.)
Check that the type, length and installation of the
connector cable match the specifications.
(Refer to 2-5 "Connection to a PC by the Host Link",
page 32, and 2-6 "Connection to a PC by the NT
Link", page 43.)
Set the PC termination resistance correctly.
Make the unit number settings again so that there is
no duplication. Refer to "Setting Unit Numbers (NT
Link 1:N Only)" (page 74).
Disconnect the communication cable from the
source of the noise and insert a noise filter in the
power supply line.
Disconnect the communication cable from the
source of the noise and insert a noise filter in the
power supply line.
Test the touch panel using "I/O CHECK" in the
maintenance mode.
Section 7-1