The hot restart feature, introduced with RTE 34.29.0, allows the user to perform notable data saving functions of the application in use when the control is turned off.

The procedure should be done in a controlled manner either before removing power or through an input from the Uninterruptible Power Supply (UPS).

The user can enable this management by entering the WARM_RESTART command in the RTE.cfg file (not recommended), specifying an input channel that causes the start of data saving (WARM_RESTART_ACTIVE -> warm_rst.(8)=1 or from project configurator (recommended) (settings->general->system->warm restart)) and an optional output that is triggered at the end of warm restart operations (WARM_RESTART_INFO_SAVED -> warm_rst.(10)=1 or from project configurator (settings->general->system->warm restart)).

On the rising logic edge of the WARM_RESTART_ACTIVE signal, all PowerSets are disabled. Once all PowerSets are disabled, the execution of the save routine (in timesharing) begins.

When all functions have been executed:

•a flag in the retentive parameter WARM_RST is set

•the output WARM_RESTART_INFO_SAVED is set, if configured

•the loading mode is set

At the next switch on, using the WARM_RST parameter, if the save was successfully completed then all the reset routines are executed in sequence. This operation is performed before setting the EtherCAT lines to OPERATIONAL mode (to make sure that the outputs are set correctly).

WARM_RESTART management is enabled immediately before the EXECUTION mode is set (timesharing enable).

From RTE 34.30.4, with WARM RESTART enabled, if during the start phase the control is turned off (before the end of the restore procedure), the next time it is switched on it will try to restore the previously stored conditions. Previously, the presence of the data for restoring was invalidated.

Correlations

When WARM_RESTART_ACTIVE is active:

•(PowerSet) causes the power drop due to lack of global feedback; after all PowerSets are disabled, the warm restart save routine is initiated.

NOTE: So if WARM_RESTART_ACTIVE is not active it is implicitly added to the PowerSet global feedbacks, causing the feedback mask to contain an extra bit than the configured ones.

•(SYS_LOG/SYS_DUMP) all operations to create log or dump files are aborted

•(Alarms) axis alarms and fieldbus diagnostic alarms are no longer generated

•(C0_DONE) c0_done reset handling caused by alarms is disabled

•(Profibus/ProfiNet) all communications are disabled

•(DeviceNet slave) all communications are disabled

•real speeds and accelerations are no longer updated

•real position of fieldbus transducers is no longer updated

Two new tracking points for OB functions have also been introduced (sched::obFunctionAttach):

•OFA_TS_WRST_SAVE to handle the save

•OFA_TS_WRST_RESTORE to handle restoring

Cold restart

Cold restart is performed when:

•retentive memory is lost

•the save operation is unsuccessful, alarm 9249 is generated

•the bit sys_cfg_2.18 is set

Keywords warm restart