MirkoZhou:
Thank you so much, Bronson.But according to the attached images from Instruction Manual , the light meter has two output ports(USB and RS-232). It also mentions that the RS-232 port is used for connecting with printer, whereas the USB is used for communication with PC. So I'm confused which one should I use for connecting with Arduino. The printer doesn't send any command to control the light meter through RS-232 cable, so I'm thinking should I use the USB port since it is used for connecting with PC?
On page 4, it says that you can connect to PC using cable T-A11.