I had the same problem, I think this is because I commented out the line with the Initialize
method call in the devdesc.xml.
Uncommenting the line solved the problem for me. So I think Initialize
method call should be present even if your FB that extends Raspberry Pi i2c does not implement it.
<FBInstance basename="$(DeviceName)" fbname="I2CHAT_DI6acDQ6rly">
<CyclicCall methodname="AfterReadInputs" task="#buscycletask" whentocall="afterReadInputs"/>
<CyclicCall methodname="BeforeWriteOutputs" task="#buscycletask" whentocall="beforeWriteOutputs"/>