Beckhoff EL1258, Документация

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Basics communication
EL125x, EL2258 29 Version: 2.5
Note
Data management
If slave CoE parameters are modified online, Beckhoff devices store any changes in a fail-
safe manner in the EEPROM, i.e. the modified CoE parameters are still available after a
restart.
The situation may be different with other manufacturers.
An EEPROM is subject to a limited lifetime with respect to write operations. From typically
100,000 write operations onwards it can no longer be guaranteed that new (changed) data
are reliably saved or are still readable. This is irrelevant for normal commissioning. How-
ever, if CoE parameters are continuously changed via ADS at machine runtime, it is quite
possible for the lifetime limit to be reached. Support for the NoCoeStorage function, which
suppresses the saving of changed CoE values, depends on the firmware version.
Please refer to the technical data in this documentation as to whether this applies to the re-
spective device.
• If the function is supported: the function is activated by entering the code word
0x12345678 once in CoE 0xF008 and remains active as long as the code word is not
changed. After switching the device on it is then inactive. Changed CoE values are not
saved in the EEPROM and can thus be changed any number of times.
• Function is not supported: continuous changing of CoE values is not permissible in view
of the lifetime limit.
Note
Startup list
Changes in the local CoE list of the terminal are lost if the terminal is replaced. If a terminal
is replaced with a new Beckhoff terminal, it will have the default settings. It is therefore ad-
visable to link all changes in the CoE list of an EtherCAT slave with the Startup list of the
slave, which is processed whenever the EtherCAT fieldbus is started. In this way a replace-
ment EtherCAT slave can automatically be parameterized with the specifications of the
user.
If EtherCAT slaves are used which are unable to store local CoE values permanently, the
Startup list must be used.
Recommended approach for manual modification of CoE parameters
• Make the required change in the System Manager
The values are stored locally in the EtherCAT slave
• If the value is to be stored permanently, enter it in the Startup list.
The order of the Startup entries is usually irrelevant.
Fig. 24: Startup list in the TwinCAT System Manager
The Startup list may already contain values that were configured by the System Manager based on the ESI
specifications. Additional application-specific entries can be created.