Proface APL3000B - Node Box PC - Manual (Page 60)

Chapter 2 Specifications
2-33
Serial Mode Select Switches (SW4 to SW10) operate as shown in the circuit diagram below.
*1
*1 To enable RTS automatic control of the TX output driver, be sure to set SW No. 9 and 10 ON, and set
SW No.4 OFF.
To enable control of the TX output driver via RTS signals, be sure to set SW No. 9 and 10 OFF, and set
SW No.4 ON.