SR 820 is not listed in the manual. SR 830 is. I assume that SR 820 pertains to RS232 port 1. I've read the postings that detail the fixes for the SR 830 faults. I reassigned 0020 and 0021 to 2. 5001=1 5110=5, 5111=1, 5112=8. I now have no fault codes. If I unplug the cable I get SR 830.This appears normal. Pressing read and all ,makes the screen flash read,again this appears normal. My problem is when I send from the PC, the program never appears on the CNC. Did I miss a setting????