*1 R is the terminating resistance. Connect the terminating resistance (110 Ω) between terminals RDA and RDB . For details see section 2.3. *2 Connect terminal FG to earth terminal of the PC main body grounded with resistance of 100 Ω or less. However, as for the computer link unit of the A series PC, see the manual of the computer link unit. *3 The 24V DC power requirement can be taker from the service power supply of the PC