generic serial read/write: no response

Hi All,

Am trying to do generic serial call/response with firefly and an arduino uno. The intention is to use it later for g-code type read/write.

The arduino sketch running is the sample serialCallResponse. In the arduino serial monitor, the feedback is normal.
However, when trying to read or write in grasshopper, there is no msg read in.

A screenshot is posted for reference: 
*click*

Has anyone managed to get the generic serial read/write working?

Thanks for reading.