Backup feature in function block programming

Issue

All setpoints are lost after a power outage and the function block programs revert back to initial value.

Product Line

TAC Vista, SmartStruxure Solution

Environment

  • Menta
  • Function Block Editor
  • Menta Editor
  • Xenta 280/300/400 Controllers

Cause

A Menta, Menta Editor, or Function Block Editor program with configurable setpoints will be lost if the default programming settings are used and there is a power loss.

Resolution

Backup feature in function blocks

Menta and Menta Editor

  • When the Backup check box is selected, the current value of the block output and internal states in the RAM are used when the device makes a warm start. Otherwise, the block output and internal states are reset to their initial values (same as for a cold start) at a warm start if the Backup box is not checked.
  • If a power outage lasts longer than the power failure protection time for the device and the RAM contents are lost, the restart is a cold start. All blocks will be rest to their initial states regardless of the Backup option.
  • The RAM working member that includes current values will last for 72 hours without power.

Function Block Editor

  • When the Backup check box is selected, the current value of the block output and internal states in the RAM are used when the device makes a warm start.
  • If a power failure occurs, all important variables are automatically saved to the flash memory before complete shutdown. When power returns, this data retention function ensures that the Automation Server can continue to run with the correct set of values.