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Troubleshooting Section 11-2
11-2-6 Other Errors
Communications Errors
â– CPU Unit Indicators
POWER Lit
RUN Lit
ERR/ALM ---
INH ---
BKUP Not lit
PRPHL ---
Seven-segment
display
Probable cause and possible remedy
None An error has occurred in the communications between the periph-
eral port and connected device. Confirm that the peripheral port
settings in the PLC Setup are correct.
An error has occurred in the communications between the RS-
232C port and connected device. Confirm that the RS-232C port
settings in the PLC Setup are correct. Check the cable wiring. If a
host computer is connected, check the serial port settings and
program in the host computer.
POWER RUN
INH
PRPHL BKUP
ERR/ALM