Operating data (without Hybrid EMS)

Last modified: 03 Mar 2025

Under Power control > Operating data, you can view a summary of system data related to power control functions. This overview is divided into several sections, which are explained in more detail below.

1. Controller operation

The blue'Log can be operated in three different modes:

Standalone: Only one blue'Log is used for controlling your system.
Master: Several blue'Logs are required for large-scale control over your system, with the devices running in master-slave operation. The master blue'Log XC sends signals to a slave blue'Log XM.
Slave: A slave blue'Log XM receives signals from the master blue'Log XC.

For details about each operating mode, see Controller operation modes: standalone, master, slave.

2. Plant data

You can configure the electrical characteristics of your plant under Plant data. All settings are mandatory except for the Extended settings.

Parameters

Select a parameter to view more details.

Agreed connected active power Pav

The maximum power the power generating system is permitted to feed into the grid, as determined by an agreement between the grid operator and the subscriber.
Example: A plant with 9000 kW of installed capacity may be restricted to 1000 kW of feed-in power based on the agreement with the grid operator.

Agreed supply voltage Vc

The voltage at the point of common coupling (PCC) as agreed upon by the grid operator and the subscriber. In most cases, this matches the nominal system voltage (V_n), but if a different voltage is specified in the agreement, that value is used as V_c.

Agreed connected apparent power Sav

The apparent power of the power generating system. This is calculated as the quotient of the agreed connected active power (P_av) and the lowest power factor (cos φ) specified in the agreement between the grid operator and the subscriber.

Nominal system frequency Fn

Nominal value of the grid frequency.

Installed active power Pinst

The sum of the nominal power of every power generating unit within the power generating system.
This parameter can be configured under the Extended settings.

Maximum apparent power of the power generation system SA max

Highest 10-minute average value of the apparent power of the power generating system.
This parameter can be configured under the Extended settings.

Feed-in meter

For open-loop operation, a meter is not mandatory. For more information on open/closed loop, see Closed loop vs open loop control (without Hybrid EMS).

3. Advanced plant data

Under Advanced plant data, you can configure irradiance and temperature sensors to make their data points accessible via Modbus.

Prerequisites

Sensors must be configured under Devices > Sensors.
The Modbus Power Control and Remote Power Control licenses are required to access these data points. See License and Data sheets.

Sensor for output of global irradiation

Here you can assign an irradiance sensor to a master or slave device.

If a device has several irradiance sensors, select the measured value to be forwarded via Modbus.
Advanced settings:
- Modbus assumes that irradiance sensors are mounted horizontally. If the sensor is mounted at an incline (for example, on a PV module), activate the toggle and enter the inclination angle (in degrees) of the sensor.

Sensor for output of ambient temperature

Here you can assign a temperature sensor to a master or slave device.
If a device has multiple temperature sensors, select the measured value to be forwarded via Modbus.

4. Calculated plant data

Grid operators, plant operators, direct marketers, or balancing service providers want to know the potential production of a PV plant.
Grid operators want to know a plant’s reactive power capability to estimate its contribution to voltage stability.
The values Available active power and Available reactive power can be read via the Modbus interfaces Modbus Power Control and Remote Power Control.
See Calculated plant data (without Hybrid EMS) for further details.

5. Slaves

The Slaves area shows all available devices that can be connected as slave devices.

Item	Name	Details
1	Green check mark	The slave is connected to this device
2	Chain icon	Connect a device as a slave to this device
3	Yellow check mark	The slave is connected to another device
4	Arrow icon	Access the web interface for this slave device
5	Add device by IP	Manually add a device using its IP address