FEC AFC1500 - Manual (Page 31)

Discrete Signal Connection
The Discrete I/O Interface operates with 24VDC Sink type (True Low)
connections as a default. (Contact FEC if 24VDC Source type (True High)
connections are desired) Typical configuration connection is shown in the
figure below;
CN4: Output
CN3: Input Connector
True Low (Sinking) Logic
200 ma Maximum current (outputs)
24 VDC Operating Voltage
Discrete I/O Port Specifications
Chapter 3: Control Interfaces
31