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Troubleshooting Using LED Indicators
Section 7-2
7-2
Troubleshooting Using LED Indicators
7-2-1
LED Indicators
This section presents a number of easy to use procedures to troubleshoot
possible errors using the LED indicators on the front of the Unit (see figure
below).
The possible errors which could occur have been categorized and for each
category a group of two or three LED indicators can be used to troubleshoot
the problem:
• Unit start-up errors
These include errors in the PLC CPU, as well as errors in the Unit, which
prevents the combination from starting up correctly. Use RUN, ERC, and
ERH indicators to troubleshoot the errors.
• Operational errors
These include PLC errors, PLC Bus errors, and error log problems, all
during operations. Use RUN, ERC, and ERH indicators to troubleshoot
the errors.
• Configuration problems
These include errors during or after downloading a new configuration as
well as errors in the configuration after startup. Use ERC and PRM indica-
tors to troubleshoot the errors.
• I/O data communication errors
These include errors in the PROFIBUS interface or on the network. Use
BST, COMM and BF indicators to troubleshoot.
7-2-2
Unit Start-up Errors
Unit start-up errors are errors which occur at starting up the system and which
prevent the Unit from functioning correctly in the PLC system. Usually these
errors also cause the CS/CJ PLC CPU ERR/ALM indicator to be lit or flashing.
For more information on error indications in the PLC, refer to the
CS1 Series
CPU Unit Operation Manual
(W339) or the
CJ Series CPU Unit Operation
Manual
(W393) for more details.
The error determination procedure uses the table below. To determine the
error
• First find the status of the RUN LED indicator (left column).
• Move one column to the right and find the ERH LED indicator status.
• Move one column to the right and find the ERC LED indicator status.
The probable error causes are then listed to the right of the third column.
CJ1W-PRM21
CS1W-PRM21
PRM21
CS
CS
RUN
RUN
ERC
ERC
BST
BST
BF
BF
ERH
ERH
PRM
PRM
COMM
COMM
ERC
RUN
BF
PRM21
COMM
BST
ERH
PRM
Summary of Contents for SYSMAC CJ1W-PRM21
Page 2: ...iv...
Page 36: ...22 Basic Operating Procedure Section 1 5...
Page 52: ...38 Defining PROFIBUS DP in the Software Section 2 5...
Page 112: ...98 Allocated CIO Area Words Section 4 2...
Page 122: ...108 Command Response Reference Section 5 2...
Page 160: ...146 Replacing the Unit Section 7 8...
Page 174: ...160 Appendix...
Page 180: ...166 I O Data Conversions Appendix D...
Page 186: ...172 Configurator Error and Warning Messages Appendix E...
Page 187: ...173 Index...
Page 188: ...174 Index...
Page 190: ...176 Revision History...