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4 structure of the communication network – SMA SC 500CP XT User Manual

Page 110

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10.3.5 Behavior in the Absence of Active and Reactive Power Setpoints

In the event of failure of setpoints for active and reactive power control, the inverter is capable of bridging the gap in
two ways:

• Use of last default values received:

As long as the inverter does not receive any updated default values, it will use the last value received (when
setpoint takes place via communication) and the last valid mean value (when using analog setpoints).

• Use of substitute values:

As long as the inverter does not receive any updated default values, it will utilize the specified substitute values for
active power limitation, reactive power setpoint and displacement power factor. In this case, different substitute
values can be configured for feed-in operation and grid monitoring.

The parameter PwrMonErrMod is used to configure whether the last default values (LastVal) or the configured
substitute values (SubVal) are to be used. This setting will be valid for both active and reactive power setpoints. The
substitute values are used when the time since receiving the last valid signal for default values as defined in the
parameter PwrMonErrTm has elapsed.

Setting

Description

LastVal

If specified via communication: utilization of the last value received

In case of analog setpoints: utilization of the last valid mean value

SubVal

Use of configured substitute values

The use of the substitute values is recommended when setpoints are effected via analog sig-
nals.

P-WSubValRun: substitute value for active power limitation in feed-in operation

P-WSubVal: substitute value for active power limitation outside of feed-in operation

Q-VArSubValRun: substitute value for the reactive power setpoint in feed-in operation

PF-PFSubValRun: substitute value for the displacement power factor in feed-in

operation

PF-PFExtSubValR: substitute value for the excitation of the displacement power factor

in feed-in operation

Q-VArSubVal: substitute value for the reactive power setpoint outside of feed-in

operation

PF-PFSubVal: substitute value for the displacement power factor outside of feed-in

operation

PF-PFExtSubVal: substitute value for the excitation of the displacement power factor

outside of feed-in operation

10.4

Structure of the Communication Network

In order to connect the inverter to a computer via the service interface or via the Internet, the communication unit must
be integrated in a system network. To enable several inverters to be operated in the same network, the communication
unit of each inverter must be assigned a unique network address.

10 Function Description

SMA Solar Technology AG

User Manual

SCCPXT-BA-E4-en-54

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