PAGE 9 10 OCTOBER 1998 CH. 2 INSTALLATION RIBBON CONNECTOR TO REGULATOR BOARD U4 U16 U15 J2 U17 U14 U10 U21 U18 U11 U3 U19 U9 U 8 U16 U22 U12 U1 U2 RS-485 Port Figure 2.1 – RTU/Modbus Option Board