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Chapter 4 Performance specification
4-32
LED status during normal communication
G4L-CUEA
RS-232C
RS-422
RUN/BPS
TX/BPS
RX/BPS
ACK/DATA
NAK/PARITY
ERR/EVEN-ODD
MODEM/STOP
SYS-RUN
RUN/BPS
TX/BPS
RX/BPS
ACK/DATA
NAK/PARITY
ERR/EVEN-ODD
RS-485/STOP
SYS-ERR
4.4.2.5 Troubleshooting for dial-up modem communication
1) Modem communication of module can be checked if operated normally through LED display. Refer to Checklist
in [Table4.6] to shoot the trouble.
[Table4.8] Checklist for module’s LED
LED type
If normal
If abnormal
Action to take
RUN ON
OFF
1)
..
Run RS-232C channel operation using Frame Editor
Flash once
initially
Flash
continuously
in a cycle of 1
second
1)
Check cable connection between module and modem
2)
Reset modem initializing command referring to modem
manual
3)
Tx/Rx LEDs shall initially flash once to be normal
TX
Flash if in
Transmission
No flash
1)
Check cable connection between module and modem
2)
If in user mode, check setting of PLC program and frame
3)
If in dedicated mode, check setting of station No.
RX
Flash if in
receiving
No flash
1)
Check if phone line is connected to line terminal of modem
2)
Check status of public line
3)
Check if data is transmitted from the other station’s modem
4)
Check cable connection between module and modem if RX
LED of modem flashes while LED of module doesn’t flash.
RUN/BPS : always ‘ON’
TX/BPS : if in transmission, ‘ON’
RX/BPS : if in receiving, ‘ON’
MODEM/STOP : always ‘ON’
SYS-RUN : dimly ‘ON’