- Difference description concerning the 9400 firmware from V1.51 to V2.0

Compatibility with previous versions
Upwards compatible in terms of function.
Higher software versions support all function included in previous software versions.
Due to the increasing number of functions integrated into more recent software versions, errors may occur when parameter sets are transferred from higher software versions to lower ones.

Note:
Axis modules equipped with a firmware version ≥ 2.0 can only be managed and operated by means of an Engineer version as of 1.5. Therefore, the Engineer needs to be updated to this version before.

Function extensions
- Initial commissioning via keypad possible
- Field weakening in case of synchronous motors

Eliminated function restrictions
- Linear absolute value encoder can only partly be used
- Parameter C22 cannot be written online
- CAN sync time must be > 1 ms

The following function restrictions are only published on the Intranet:
- QSP request is cancelled with an interruption of 1ms
- The homing process is aborted without following error reset
- Incomplete initialisation of the rotative absolute value encoders
- Troubleshooting in the profile generator

Further information is provided in Service Message No. 27/2007.