Grid compliance · Germany
Westnetz-Gateway 2.0: EMS connection over IEC 60870-5-104
Connection of the EMS to the Westnetz-Gateway 2.0 over IEC 60870-5-104 (Westnetz-Profil), in accordance with the TAB Mittelspannung. The EMS receives the active-power setpoints from Westnetz, executes them across the controlled assets with the required ramp rates (VDE-AR-N 4110) and reports setpoint confirmation and measurements back. Including support for the commissioning signal test.
What is the Westnetz-Gateway 2.0?
The Westnetz-Gateway 2.0 is the telecontrol cabinet that Westnetz requires for plants above 500 kW on the medium-voltage grid. Over IEC 60870-5-104 with the Westnetz-Profil, the grid operator controls your generation or storage plant: it sets active-power setpoints, regulates reactive power and can disconnect in an emergency.
The EMS is the plant-side telecontrol device, that is, the 104 server. It connects over Ethernet (RJ45) point-to-point to the sealed, operator-owned gateway. The telecontrol function is fully integrated into the Voltmaster Controller: no separate RTU cabinet is needed.
For you as the connecting party this means: a connection that correctly receives the Westnetz setpoints, executes them with the required ramp rates and reliably reports the current state back, verified in the signal test before commissioning.
What the gateway controls
- Active-power setpoint, as a percentage of installed power, with ramp rates per VDE-AR-N 4110
- Reactive-power control, switchable between Q(U) and a Q setpoint
- Sofort-AUS (immediate off) via the transfer or coupling switch, with feedback
- Measurements cyclically and on change: active and reactive power, voltage, availability
Important: the gateway gives Westnetz no access to your business processes. The grid operator can only control the energy parameters of your plant, nothing more.
The regulatory framework
The connection follows the Westnetz TAB Mittelspannung and the VDE-AR-N 4110. Which connection applies depends on the connection power.
Low voltage
Up to 100 kW
The rules of the TAB Niederspannung (low voltage) apply.
Modbus TCP
100 to 500 kW
Connection over the Westnetz-Gateway-Light with the E.ON Modbus TCP profile, setpoint in steps.
IEC 60870-5-104
Above 500 kW
Connection over the Westnetz-Gateway 2.0 with IEC 60870-5-104 and the Westnetz-Profil.
Redispatch 2.0 and grid-security management: from 100 kW, participation in Redispatch 2.0 is mandatory. Setpoints from grid-security management always take priority over market signals. On loss of connection, the EMS holds the last valid setpoint.
How the connection is built
Four links, one continuous path from the Westnetz control system to your assets. The sealed gateway belongs to the grid operator; everything to the right of it is handled by the Voltmaster Controller.
Westnetz control system
The Westnetz SCADA sets setpoints and receives the measurements.
Westnetz-Gateway 2.0
Sealed, operator-owned telecontrol cabinet in your transfer station.
Voltmaster Controller
The plant-side telecontrol device (104 server), coupled point-to-point over Ethernet.
Your assets
Battery storage, PV and other controlled generators.
The control loop, visualised
The grid operator commands, the controller regulates, the site reports back
The grid operator sets a power limit over the IEC 60870-5-104 protocol. The Voltmaster Controller ramps the assets down in a controlled way and feeds the measurements back in real time, with an independent hardware emergency stop that the controller executes through its IO extension as a safety net.
How Voltmasters connects
The Westnetz-Profil is a concrete data-point list on the IEC-60870-5-104 stack that we already run in Belgium. This is how we implement it at the plant.
- Active-power setpoint as a percentage of installed power, executed with the ramp rates per VDE-AR-N 4110
- Holding the last setpoint on loss of connection, plus setpoint persistence across a restart
- Reactive-power control Q(U) and Q setpoint, remotely switchable, with voltage limiting
- Sofort-AUS via the transfer or coupling switch, with a collective feedback signal
- Measurement on the medium-voltage side, plus extra values such as available power, plant availability, storage SoC and irradiance for PV
- Operational safety: self-monitoring, a hardware life contact and a battery-backed station supply
Commissioning and signal test
Commissioning of the Westnetz-Gateway 2.0 runs in four steps. We prepare each step and support the signal test with Westnetz. The test communication is conducted in German.
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1
Bittest Anschlussnehmer
Self-test of all data points on the plant side, before the grid operator is involved.
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2
Hochlaufprüfung
The grid operator checks remotely, via a general interrogation, that all signals come through cleanly.
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3
Bittest VNB and Quelle-Senke-Prüfung
On-site check with Westnetz, point by point in both directions.
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4
Funktionstest Gesamtwirkungskette
Real curtailment above 30 percent of rated power, no simulation, often combined with step 3.
Good to know: Westnetz can also run function tests unannounced. A cleanly tested and documented connection therefore pays off across the whole operating life, not just at handover.
100 to 500 kW
Smaller plants: the E.ON Modbus TCP profile
If your plant is between 100 and 500 kW, the connection is not over IEC 104 but over the Westnetz-Gateway-Light with the E.ON Modbus TCP profile. That is a separate integration, which we implement cleanly separated.
To the E.ON profile and the grid operatorsRoadmap
Other E.ON grid operators
Bayernwerk Netz, Avacon Netz, E.DIS Netz and Schleswig-Holstein Netz publish their own, closely related IEC-104 profiles. At that level this is a roadmap topic: we port the data-point lists project by project as soon as a concrete project comes up.
See all grid operatorsPlanning a connection to the Westnetz-Gateway 2.0?
Tell us the connection power, the voltage level and your assets. We configure the Westnetz-Profil, test all signals in advance and support the signal test at commissioning.
FAQ
Frequently asked questions about the Westnetz-Gateway 2.0
From what power level does the Westnetz-Gateway 2.0 apply?
The Westnetz-Gateway 2.0 with IEC 60870-5-104 applies to plants above 500 kW on the medium-voltage grid (10/20 kV). From 100 to 500 kW the connection is over the Westnetz-Gateway-Light with the E.ON Modbus TCP profile. The decisive figure is the total power at the grid connection point.
Do I need a separate telecontrol device besides the EMS?
No. The telecontrol function is integrated into the Voltmaster Controller; the EMS is the 104 server on the plant side. It connects point-to-point over Ethernet to the sealed Westnetz gateway. No additional RTU cabinet is needed.
Which protocol does the Westnetz-Gateway 2.0 use?
IEC 60870-5-104 with the Westnetz-Profil, a concrete data-point list per the TAB Mittelspannung. We already run the same IEC-104 stack in Belgium for Fluvius telecontrol; the Westnetz connection is the port onto the Westnetz-Profil.
How does the signal test at commissioning work?
In four steps: Bittest Anschlussnehmer as a self-test, Hochlaufprüfung via a remote general interrogation, Bittest VNB with the Quelle-Senke-Prüfung on site, and the function test of the full effective chain with real curtailment above 30 percent of rated power. We prepare each step and support the test.
Is the EMS certified with Westnetz?
There is no formal certification for the customer-side device. Approval effectively happens through commissioning and the successful signal test. Whether an additional EZA-Regler (plant controller) per VDE-AR-N 4110 is required depends on the plant configuration and is clarified per project.
What happens if the connection to the gateway is lost?
The EMS holds the last valid setpoint and keeps it across a restart. The plant therefore stays in a grid-compliant state until the connection is restored and a new setpoint is present.
Sources
Official sources and standards
This page is based on the grid operator and standards documents below. Always check the most recent version at the publisher.
Looking for the technical details and step-by-step configuration? You will find them in our documentation.
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