Omron NT-series Programmable Terminal V022-E3-1 - Manual (Page 44)

Reference
Section 2-3
3-3 Connecting to the Support Tool
Connect the NT600S to a computer with an RS-232C cable to transfer the screen
data created by using a support tool to the NT600S.
In other than C200H direct communications, it is impossible to connect a computer
and the Host that are used to run the support tool at the same time. Connect a
computer only for transferring the screen data.
Communication conditions
Communication conditions are set when a support tool is started.
It is impossible to connect a computer and a PC/Host at the same time to the
NT600S. Connect a computer only to transfer the screen data.
To make a connector cable, refer to Appendix H Making the Cable for Connec-
tion to the Support Tool (page 278).