I recently did a simular project. I connected the PLC RS232 connection to a "dog catcher" made by brigantine electronics.
This device works well, if you send the data using a Print #1 "String of data in CSV format".
The device saves what you send to it in a txt file on a usb flash stick. you can rename the txt file to .csv and then open the sorted logged data in excel.
website is :
www.brig-elec.comCheers.