Siemens CP 443-1 Manual page 63

Diagnostics
Diagnostics of the port settings for the CP described here is possible only using the
entries in the diagnostic buffer over SNMP, NCM diagnostics, and the LED
displays.
Further Notes:
S 10/100 Mbps network components without "Autonegotiation"
If you use 10/100 Mbps network components that do not support
"Autonegotiation", it is possible that you will have to set the mode manually.
S Forcing a specific mode instead of "Autonegotiation"
If your application requires a fixed mode instead of "Autonegotiation", you will
need to match up the partner devices.
S No reaction to Autonegotiation query with manual configuration
Remember that if you configure the CP manually, it will not react to an
autonegotiation query! As a result, a connected partner will not be able to set
the required mode and communication will not be ideal.
Example:
If, for example, the CP is set to "100 Mbps − full duplex", a CP connected as
partner will set "100 Mbps − half duplex". Reason: Due to the fixed setting, no
autonegotiation response is possible; the connected partner recognizes the 100
Mbps with autosensing but nevertheless remains in half duplex.
S Recommendation: Change individual network settings only over MPI.
If you modify the LAN settings in the properties dialog of the CP in the "Port
Parameters" tab using the "Transmission medium/Duplex" option, these
changes will be adopted by the CP and activated when the configuration data is
downloaded to the CP.
We therefore recommend that you download configuration data to the S7
station over an MPI connection if you change this setting.
If you download the configuration data over the LAN interface, depending on
the selected setting, it is possible that the current download will not be
completed due to the changes to the configuration taking immediate effect and
an inconsistent configuration is reported.
Example:
The download is started initially with the setting TP/ITP at 10 Mbps half duplex.
If the "Individual network setting" is now changed to 100 Mbps full duplex, the
download cannot be completed.
CP 443-1 Advanced for Industrial Ethernet / Manual Part B4A
Release 01/2007
C79000-G8976-C193-06
10 Further Notes on Operation
B4A−63