This article explains what external control signals and schedules are, and how they extend load management in the gridX Energy Management System (EMS).
What are external control signals and schedules?
External control signals and schedules allow the EMS to adjust charging power. This includes time-based schedules, hardware input signals, and power limitation signals from the Distribution System Operator (DSO).
All external control features build on top of load management. Load management must be active and correctly configured before any external control signal or schedule can take effect.
Available features:
Scheduled charging — configures a maximum power import limit for specific times of day
IO devices — uses hardware input channels to trigger GCP limit changes in response to external signals (for example, from a fire alarm or grid relay)
DSO signaling — receives active power limitation signals from the grid operator via an external controller, using VDE 4110 compliant communication
§14a EnWG compliance — implements the EnWG §14a regulation in Germany, enabling DSOs to curtail charging power when the grid is congested in exchange for reduced grid fees
What are schedules used for?
Schedules are a generic way to set recurring power import limits without reacting to live signals. A schedule defines a maximum charging power for a given time window and repeats automatically.
Schedules can be configured manually in the XENON Dashboard or set programmatically via the gridX API. This allows external systems to define or update limits without direct user interaction.
How do external control signals and schedules interact with load management?
External control signals and schedules apply as additional constraints on top of the load management power limit. They can only further reduce the available charging power — they cannot exceed the total import limit configured in the system settings.
When multiple constraints are active at the same time, the most restrictive limit applies.