Omron NT20S - Maintenance of the NT20 S

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Maintenance of the NT20S
Section 7-3
Message Cause Remedy
(ACIA)
Parity Error
Framing Error
Communication parameters/
conditions of communications set
incorrectly.
Check whether the parity bit, frame length, baud rate,
stop bit length, and flow control settings of the PC
match the settings of the NT20S.
F
ram
i
ng
E
rror
Overflow Error
Overrun
Noise caused data corruption during
communication.
Use a noise-resistant cable if communication occurs
in an environment with high levels of noise.
Overrun
The connectors of the connecting
cable are not connected correctly.
Reconnect the cable.
Buffer Overflow The NT20S receive buffer is full. Lengthen the command transmission intervals. If this
error occurs frequently, set flow control for
communications.
Time Out The connectors of the connecting
cable have become disconnected.
Reconnect the cable.
The PC is stopped. Make sure the PC is able to communicate with the
NT20S.
During transmission of one
command a time lapse exceeding 5
Confirm the proper command length.
command, a time lapse exceeding 5
seconds is detected.
Reconnect the cable.
NAK Received
(end code simultaneously
displayed)
Noise caused data corruption during
communication.
Use a noise-resistant cable if communication occurs
in an environment with high levels of noise.
Check the end code by referring to the PC user’s
manual.
Unit No. Error The unit # does not match that set on
the PC.
Set the PC unit # to “0”.
The PC is transmitting incorrect data. Check PC operation.
Noise caused data corruption during
communication.
Use a noise-resistant cable if communication occurs
in an environment with high levels of noise.
FCS Error The PC is transmitting incorrect data. Check PC operation.
Noise caused data corruption during
communication.
Use a noise-resistant cable if communication occurs
in an environment with high levels of noise.
7-3 Maintenance of the NT20S
Carry out maintenance work in order to ensure that the NT20S is always used in its
optimum condition.
WARNING: Do not attempt to take the PC apart and do not touch any internal parts while the
power is being supplied. Doing either of these may result in electrical shock.
Spare PT It is advisable to have a spare NT20S available to minimize system downtime in
the event of an NT20S failure or if the screen display becomes difficult to read due
to deterioration of the display unit.
Backlight When the backlight in the display is getting dim and the screen cannot be read eas-
ily, replace the backlight. The backlight can be replaced at the rear of the NT20S
while it is mounted in an operation panel.
S Replaceable Backlight Model
NT20S-CFL01