Usually, sure. But some inverters can do it.the PV will backfeed the generator with a possibly catastrophic result for the generator.
This is from the files.sma.de link from the previous comment.
The purpose of the DIGIN or Digital Input is to signal to the Sunny Island that there is a backup generator available when the public utility power is lost. This allows the Sunny Island to call for a generator with a two wire start. Along with calling for a remote start generator, it will provide reverse power protection in order to prevent any renewable energy current from back feeding to the generator.