AH500 Quick Start 2.3.2 Wiring the Digital Input Module The input signal is the direct-current power input. Sinking and sourcing are current driving capabilities of a circuit. They are defined as follows. Sinking Sourcing 2.3.3 Wiring the Digital Output Module The output unit can be the relay output, the transistor output, or the TRIAC output. Relay output Transistor output 2-8 ① Alternating-current power supply: 100~240 VAC, and 50/60 Hz ② Circuit breaker ③ Emergency stop: The emergency stop button can be used to cut off the power when an emergency occurs. ④ Power indicator ⑤ AC power load ⑥ Fuse (2A) ⑦ The ground impedance is less than 100 Ω. ○8 Direct-current power supply: 24 VDC