Fail-safe operation (active power)

Last modified: 2026-04-23

Communication failure with a meter

For accurate active power control, the bluelog Neo relies on measured data from a connected meter. If the meter fails, or if communication is temporarily lost, the bluelog will go into predefined error behavior.

Since the feedback signal from the grid connection point is no longer available, closed-loop control is not possible. In this case, the bluelog switches to open-loop operation and applies the error behavior.

The error behavior is only activated after a user-defined waiting time has elapsed. During this time, it continues to control the PV and battery systems using the last values sent to the inverters.

There are two options for the error behavior:

Default value: Define a default value to be sent to the inverters.
Hold last value: The last calculated correction value is sent to the inverters.

Note

If the meter fails, the grid operator can further curtail the active power of a plant. Due to the missing measured values, the grid operator can no longer implement control at the grid connection point (feed-in/import limitation).

Example 1

Error behavior: Default value = 0%
Waiting time: 5 seconds
Last value sent to inverters = 50%

After a communication loss, the bluelog first continues to send 50% to the inverters for 5 seconds. After 5 seconds, the bluelog switches to the configured default value of 0%.

Example 2

Error behavior: Hold last value
Waiting time: 5 seconds
Last value sent to inverters = 50%

After a communication loss, the bluelog continues to send 50% to the inverters.

Communication failure with the grid operator

See Grid operator commands.

Communication failure between a bluelog master and slave

In a master-slave setup, the bluelog master sends the error behavior that has been configured for meter failure cyclically to the bluelog slave.

If a communication failure between the master and slave occurs, the slave adopts the error behavior and acts accordingly.

Configure fail-safe operation for a meter

Prerequisites

None

Steps

Go to Power control > Active power > Fail-safe operation.
Under Meter failure, select the Default setpoint or Hold last setpoint for both PV and battery.
If you selected Default setpoint, enter the Fallback value as a %.
Enter a waiting time in seconds. The default is 60 seconds.

The error behavior is configured.