As to the first post, the first thing I would do is make sure you use a 3 wire cable, i.e. jumper out the hardware handshake pins on both ends of the cable, and just use TX, RX & ground, there are many threads here that explain it.
For cs_sas, I would recommend two books, Computer Numerical Control by Warren S. Seames and Computer Numerical Control Programming by Michael Save & Joseph Puszai.
Between the two they cover most areas and different controllers.
You can also use a free simulator for testing you programs, MicroTech CNCsimulator.
Al.
CNC, Mechatronics Integration and Custom Machine Design
“Logic will get you from A to B. Imagination will take you everywhere.”
Albert E.