Chapter 6 Control Terminals MS300 Figure 6-4 Figure 6-5 When the photo coupler uses the internal power supply, the switch connection for Sink and Source modes shows as Figure 6-2 and Figure 6-3: MI-DCM: Sink mode; Transistor output terminals (MO1, MO2, MCM) MI-+24 V: Source mode. Connect the digital outputs to the correct polarity. When connecting a relay to the digital outputs, connect a surge absorber across the coil and check the polarity. 6-3