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248
Hardware Faults
Section 7-1
7-1
Hardware Faults
When a fault relating to the operation of the NT20 occurs, find the symptoms
in the table below and respond by following the corresponding “Remedy” indi-
cated in the table.
Note
1.
Confirm system safety before turning the power ON/OFF or resetting.
2.
Do not disassemble the PT for repair or modification.
NT20 Symptoms
Cause
Remedy
Nothing is displayed on
the screen
Power is not being supplied.
Check the connections and make sure that power is
supplied correctly.
(Refer to
2-2-3 Power Supply Connection
, page 23.)
Power supply fuse has blown
Contact your OMRON service center.
Screen #0 has been read at the host. This is not an error. Change the screen number.
(Refer to
4-3 Screen Display
, page 140.)
Communications with the
Support Tool not possible.
The Transmit Mode has not been
established.
Display the system menu and select the Transmit
Mode. (Refer to
3-6 Registering the Screen Data
,
page 102.)
Not connected to the Support Tool.
Check the installation of the connector cable. (Refer
to
2-4 Connecting the NT Support Tool
, page 35.)
The PT type/direct connection
settings made at the Support Tool do
not agree with the NT20.
Make the PT type setting and direct connection set-
ting in the “PT Configuration” of the Support Tool
agree with the NT20.
Cannot communicate with
the PLC/Host.
Memory switch settings do not match. Check the communications setting in the “Memory
Switch” menu of the Maintenance Mode, and match
the PLC and NT20 settings.
(Refer to
3-5 Setting the Conditions of Communica-
tions with the Host by Using the Memory Switches
,
page 91.)
NT20 and PLC are not correctly con-
nected.
Check that the type, length and installation of the
connector cable match the specifications.
(Refer to
2-4 Connecting the NT Support Tool
,
page 35,
2-6 Connecting to the RS-232C Port at the
Host
, page 44.)
When NT link (1:N), there is unit num-
ber duplication.
Set again with no duplication.
Power not supplied to the NT20, PLC,
or host
Check the power supply.
Buzzer sounds, RUN LED
is OFF.
Malfunction due to external noise.
Distance the communications cable from the source
of the noise and insert a noise filter in the power sup-
ply line.
Touch panel does not
respond
Malfunction due to external noise
Distance the communications cable from the source
of the noise and insert a noise filter in the power sup-
ply line.
Touch panel is broken.
Check the touch panel by performing the touch panel
test in the I/O check in the maintenance mode.
PLC mode changes to
monitor mode.
The NT20 changes the mode during
host link communications.
This is normal with the NT20 specification. When
using a PLC that can also be connected using the NT
link, connect it with the NT link (the mode is not
changed when using the NT link).
Summary of Contents for NT20
Page 1: ...Programmable Terminal Cat No V091 E1 01 NT20 USER S MANUAL ...
Page 2: ...NT series Programmable Terminal User s Manual Produced March 2007 ...
Page 3: ...iv ...
Page 5: ...vi ...
Page 9: ...x TABLE OF CONTENTS ...
Page 15: ...xvi ...
Page 21: ...xxii EC Directives 6 ...
Page 37: ...16 Before Operating Section 1 6 ...
Page 153: ...132 Transferring the Resource Data Section 3 11 ...
Page 185: ...164 Numeral Setting Section 4 8 ...
Page 267: ...246 Key to Programs Section 6 8 ...
Page 281: ...260 Specifications Appendix A ...
Page 285: ...264 Transporting and Storing PTs Appendix C ...
Page 303: ...282 Function Restrictions Depending on the Support Tool Appendix I ...
Page 307: ...286 Index ...
Page 309: ...288 Revision History ...