Omron SYSMAC CJ1W-PRM21, Operation Manual

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133
Troubleshooting Using LED Indicators
Section 7-2
7-2-5 Network Errors
Network errors are errors which occur when attempting to startup a network,
i.e. the PROFIBUS-DP Master Unit has been switched to CLEAR or OPER-
ATE mode. The Unit will parameterize the slave stations and start data
exchange. An error in this process can be determined by examining the BST,
COMM and BF LED indicators.
The error determination procedure uses the table below. To determine the
error
• First find the status of the BST LED indicator (left column).
• Move one column to the right and find the COMM LED indicator status.
• Move one column to the right and find the BF LED indicator status.
The probable error causes are then listed to the right of the third column.
Network Errors
BST COMM BF Probable cause Correction
Not lit Not lit Not lit The PROFIBUS-DP Master Unit is in
OFFLINE or STOP mode. No communica-
tion over the network. Switch the Unit to either CLEAR or OPER-
ATE mode.
Lit A hardware error has occurred in the
PROFIBUS interface of the Unit, or a Mas-
ter station has been detected beyond the
Highest Station Address. The Unit has
switched to OFFLINE.
This indicates faulty wiring, broken mes-
sage, short-circuits, or faulty bus timings.
• Check the network wiring, and make sure
it is correct (not too long, long stub lines,
etc.)
• Check for short-circuits.
• Check the bus timing set in CX-Profibus.
• Check if any other faulty devices are on
the same network.
• Switch the Unit to CLEAR / OPERATE
mode again.
A protocol error has occurred in the PROFI-
BUS interface of the Unit, the Unit has
switched to OFFLINE.
This indicates lost tokens, or an active sta-
tion detected beyond the Highest Station
Address setting (HSA).
• Check the network wiring, and other
Master devices on the network. Make
sure they are all correct.
• Check the HSA setting in the DTM’s Bus
Parameter tab. Set it to the highest mas-
ter address which is on the network.
• Check if any other faulty devices are on
the same network.
• Switch the Unit to CLEAR / OPERATE
mode again.
A Double-Address error has occurred on
the network, i.e. there is a second Master
Unit with the same PROFIBUS address on
the network. the Unit has switched to
OFFLINE. • Check the Master devices on the net-
work. Make sure they all have unique net-
work addresses.
• After correction, switch the Unit to
CLEAR / OPERATE mode again.
Lit Not lit Not a valid combination.
Lit Not a valid combination.