Can NS-series And NT-series Programmable Terminals Be Used Together On One RS-232C Port Or One RS-422 Port On A PLC?

Yes, it is possible if you use 1:N NT Links. It is done the same way as wiring or settings for NS-series or NT-series only.

However, 4-wire RS-422 must be used.

NS-series do not support RS-485 (two-wire). Also, when an RS-232C port on the Programmable Controllers is used, NT-AL001 RS-232C/RS-422 Link Adapter is necessary.