Network Router User Manual

Commissioning
6-10
Automation System S7-400 Hardware and Installation
A5E00850741-01
6.6 Cold, Warm, and Hot Restarts with the Mode Selector
Switch
Restart (warm start)
• A r estart resets the process image and the non--retentive flags, timers, times
and counters.
Retentive flags, times and counters r etain their last valid value.
All DBs assigned the “Non Retain” attribute are reset to load values. The
remaining DBs retain their last valid value.
• Program execution is restarted at the start position (startup OB or OB 1).
• After a power supply interruption, the warm restart function is only available in
backup mode.
Hot restart
• Wihen a hot restart is performed, all data and the process image retain their last
valid value.
• Program execution is resumed at the breakpoint.
• The outputs do not change their status until the current cycle is completed.
• After a power supply interruption, the hot restart function is only available in
backup mode.
Control sequence for restart (warm restart) / hot restart
1. Set the switch to STOP.
Result: The STOP LED is lit.
2. Set the switch to RUN.
Whether the CPU executes a restart / hot restart depends on the C PU
configuration.