ZKTeco X7 - Connected with Other Parts; Connecting External Components; Connect with Power; Power Input Requirements

III
Only devices with an alarm ≤ DC 12V can be connected.
Input DC 12V, 500mA (50mA in idle status) Positive is connected with
+12V, negative is connected with GND (do not reverse the polarities).
4. Connected with Other Devices
5. Connect with Power