Thanks Xavier for recommending my article
Harry,
ExcelTransformBean only converts the XLSX to XML, which only brings you half the journey. On the receiver channel, you should then use MessageTransformBean with SimpleXML2Plain conversion to convert the XML to CSV.
To summarise,
i) Create custom module ExcelTransformBean and deploy
ii) Add ExcelTransformBean into module chain of FTP sender channel
iii) Add MessageTransformBean into module chain of NFS receiver channel
Rgds
Eng Swee