115
Troubleshooting the Network
Section 4-2
4-2
Troubleshooting the Network
4-2-1
Troubleshooting Parameter Download
The PROFIBUS Master DTM provides clear error messages if downloading of
the parameters to the PROFIBUS Master Unit fails. Failure can be due to
either
• Errors or inconsistencies in the slave parameter sets, which are checked
prior to download.
• The Master DTM being unable to establish communication with the CS1/
CJ1W-PRM21 PROFIBUS Master Unit.
• A communication interruption of the process during download.
Errors in Slave Parameter
Sets
The error messages displayed will provide a clear indication of the problem.
A download initiated by the user, starts with a check on the slave parameter
sets. The Master DTM will check
• The total number of slave devices assigned, which must be at least one
slave device.
• The total number of I/O modules per slave, which must be at least one I/O
module per slave.
• The maximum size of the I/O data size, which must not exceed 7168
words.
• The maximum number of I/O modules, which must not exceed 4000.
• Any existing overlap in the I/O Areas configured.
• Any existing overlap in the allocated PLC memory areas.
• Availability of EM banks should any of the I/O Areas be mapped to one of
the EM Banks. Availability of the EM banks depends on the PLC CPU
type.
Anyone of these errors will abort the download process without conse-
quences for the CS1/CJ1W-PRM21 PROFIBUS Master Unit.
The error messages associated with these failures are listed in Appendix
A-2
Error Messages - Configuration
. The list also provides remedies.
Errors when Establishing
Communication
If no errors occurred during the checking phase, the Master DTM will try to
establish communication with the CS1/CJ1W-PRM21 PROFIBUS Master Unit
through CX-Server. If this fails, an error message will be displayed, indicating
a communication problem (see Appendix
A-3 Error Messages - Communica-
tion
). A failure to establish communication prior to download will have no con-
sequences for the CS1/CJ1W-PRM21 PROFIBUS Master Unit. The list
provided in Appendix
A-3 Error Messages - Communication
also provides
possible remedies.
Errors During Download
If none of the first two processes result in a failure, downloading will com-
mence. As soon as downloading has started, the data in the volatile memory
of the CS1/CJ1W-PRM21 PROFIBUS Master Unit will be overwritten.
Recovery After Failing
Download
If a failure occurs during the download process, which prevents the Master
DTM from completing the process, the user must restart the Unit manually.
Restarting the Master Unit will abort the download process in the Master Unit
and recover the previous configuration from its non-volatile memory.