SMA Data Manager L - Data Processing and Time Behavior

3 Product Overview
SMA Solar Technology AG
Technical InformationSMAModbus-ennexOS-TI-en-1012
Changing the Modbus port
If you change one of the communication ports, you must also change the corresponding Modbus port of a
connected Modbus/client system. Otherwise the SMA product can no longer be accessed via the Modbus
protocol.
3.6 Data Processing and Time Behavior
In this Section, you can find typical data-processing and reaction times of the Speedwire Modbus interface and time
details for saving parameters in SMA products.
NOTICE
Damage of SMA products due to cyclical changing of parameters
The parameters of SMA products that can be changed with writable Modbus registers (RW) are intended for long-
term storage of device settings. Cyclical changing of these parameters leads to destruction of the flash memory of
the SMA products. These parameters are marked with (see Technical Information "Parameters and Measured
Values").
Parameters for grid management services to control and limit the nominal PV system power are an exception. Such
parameters can be changed cyclically. These parameters are marked with (see Technical Information
"Parameters and Measured Values").
• Do not change device parameters cyclically.
• Use the parameters for grid management services for the automated remote control.
• Note the explanation of the symbols (see Technical Information "Parameters and Measured Values").
Processing time of setpoints
The signal runtime of the SMA product with Modbus interface is usually 150ms. The signal runtime is the time required
by the SMA product to process incoming Modbus setpoints.
Implementation time/reaction time of setpoints
The physical reaction time of SMA products is normally approx. 1 second. The physical reaction time is the time
between the changing of setpoints in a SMA product until their physical implementation. Such a change would be, for
example, changing cosφ.
Data transfer interval via the Modbus protocol
For system stability reasons, the time period between data transfers via the Modbus protocol should be at least
1second. No more than five parameters and measured values should be simultaneously transmitted.