Quote Originally Posted by Boyan Silyavski View Post
you need to keep on eliminating reasons and i can tell you straight away that i would never use USB-RS232 converter for connecting to servos, or anything. . You need a normal. PC with a normal PCI port and an adapter there. Or even better, a PC with a com port that you could control from bios.


Standard RS-232C RS-422A

specifications
Communications
method
Asynchronous (ASYNC)
Baud rate 2,400 bps
Start bits 1 bit
Data 8 bits
Parity None
Stop bits 1 bit

That above is from your servo drive manual. If baud rate is not set at Com port same same, communication will NOT ever happen



And most of all check that manual https://www.fa.omron.com.cn/data_pdf...8d-u.pdf?id=68 for the proper connection to the drives from the PC side . Check your cabling if is right.


So in other words from page 1-7 seems you need Null Modem Cable https://www.decisivetactics.com/supp...h-serial-cable


Click image for larger version. 

Name:	servo omron rs232.PNG 
Views:	875 
Size:	173.7 KB 
ID:	22409
Many thanks Boyan - that's really helpful. I'll check all the above. I do have a PC with a RS-232 port and have tried connecting with that, but I didn't check any of the settings. I'll check the cable too.