Parameterization and commissioning
4.3.6
1-second UPS (Uninterruptible Power Supply)
Technical concept
The 1-second UPS is an UltraCap capacitor, which, in the event of a voltage outage, continues to supply
power to the processor for approx. 4 to 5 seconds, so that persistent data can be saved. Data saving
generally takes less than 4 to 5 seconds. However, due to ageing of the components used, one should
assume that the UPS can provide power for a maximum of 1 second. You can assume that data saving
continues to work smoothly, even after many years. If you save data yourself, we recommend that this
should take place within 1 second. Should it take longer, we would advise against it.
The 1-second UPS supplies neither the K-bus nor the E-bus with power. Please note that the data of these
devices may already be invalid when the 1-second UPS is activated. Also, the fieldbus system (or Ethernet)
may not work or not work properly once the 1-second UPS was activated.
Saving of the persistent data only takes place in conjunction with the function block FB_S_UPS_CX80xx.
This block must be called cyclically. We strongly recommend using the default values for the block.
Saving and loading persistent data
The persistent data are stored on the SD card as a wdp file. When the PLC starts up, the wdp file is loaded
from the SD card, saved there as a wd~-file (backup), and then deleted. Another current wpd file is not
written until the system is shut down or the 1-second UPS is activated. If no wdp file is present when the CX
starts up, the persistent data are invalid and are deleted (default setting).
The reason is that the 1-second UPS was activated before the TwinCAT PLC was started during startup of
the CX. In this case no persistent data were saved, since the system was unable to ensure sufficient buffer
time for saving the data.
Loading a backup of the persistent data
To load the persistent data from the backup (wp~-file), it has to be enabled in the System Manager.
Or via the following registry entry:
[HKEY_LOCAL_MACHINE\SOFTWARE\Beckhoff\TwinCAT\Plc]"ClearInvalidPersistentData"= 0
The default factory setting is "1".
CX8080
33
Version: 1.0.0
