1-second UPS (persistent data)
CX50x0 63Version: 1.9
5 1-second UPS (persistent data)
Loss of data
The use of the 1-second UPS outside of the documented possibilities can lead to loss or corruption
of data.
Use only TwinCAT to control the 1-second UPS and save only persistent data with a maximum size
of 1 MB.
The 1-second UPS is an UltraCap capacitor that continues to
supply the processor with power in the event of a power failure.
During this period persistent data can be saved, which are
available on switching on again.
Since the 1-second UPS is designed for the entire service life,
the holding time is considerably longer with new devices. The
capacitors age over the course of time and the holding time
decreases. Therefore a maximum of 1MB persistent data can
be reliably saved over the entire service life.
Do not save any other data and do not use any other
applications to control the 1-second UPS.
Please note that the 1-second UPS does not supply power to the K-bus or the E-bus and that their data 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.
Storage location and names of the files:
The persistent data are saved by default in the TwinCAT boot directory:
Development environment File path File name
TwinCAT 2 C:\TwinCAT\Boot\ TCPLC_T_x.wbp
TCPLC_T_x.wb~ (Backup)
The x in the file name stands for the number
of the runtime system.
TwinCAT 3 C:\TwinCAT\3.1\Boot\ Port_85x.bootdata
Port_85x.bootdata-old (Backup)
The x in the file name stands for the number
of the runtime system.
This section explains how persistent variables are configured for an Embedded PC:
• In the case of the CX50x0, check whether the 1-second UPS is activated or deactivated in the BIOS
(see: BIOS settings [}64]). Configure the Windows write filter and issue the corresponding write
permissions in order to be able to save persistent data (see: Windows write filter).
• Declare important data such as counter values in the PLC as VAR PERSISTENT. Then call the
function block FB_S_UPS cyclically in TwinCAT in order to control the 1-second UPS (see: FB_S_UPS
[}66]).
• Select the mode in the function block in order to specify what should happen in the case of a voltage
failure. Specify, for example, whether persistent data are saved and a quick shutdown is executed
(see: Mode and status of the function block [}68]).
• Subsequently you can check the validity of the variables and monitor whether the persistent variables
are loaded without error (see: Checking the validity of the variables [}69]).
Sample project:
https://infosys.beckhoff.com/content/1033/CX5000_HW/Resources/pro/213059083.pro
Components Version
TwinCAT on the development PC and on the control system TwinCAT 2.11R3 Build 2047 (or higher)
TwinCAT 3.1 Build 4018 (or higher)