Isolated RS422 Interface Circuit
The PC RXD pin can only receive the data when the RS232 handshake lines are set accordingly,
RTS = 1 (at +ve supply level)
DTR = 0 (at -ve supply level)
For printing the pcb files on HP laser printer download the PCBs.zip file and run the Laser.bat file after extracting
from the zip file.
Figure 2 & 3 shows the component layout of the RS422 single sided pcb and the track patterns respectively.