A: Check if the manual requires a hardware handshake (RTS/CTS). Many ZK5KX models use 2-wire RS-485 half-duplex. You may need a converter that supports auto-direction control.
Long press the button to toggle the top display line between input voltage and output voltage. On/Off State : zk5kx manual
The limit current can be finely tuned from . Operating Modes: A: Check if the manual requires a hardware