8
Installation
Power connection
•
Do not share the power with the access controller.
•
If the power is shared by other devices, it should provide 9-18 V and a minimum of 500 mA.
•
If the power is shared by Wiegand devices, it is recommended to provide 12 V and 2.5 A.
RS-485 connection
•
RS-485 should be AWG24, twisted pair, and maximum length is 1.2 km.
•
Connect a termination resistor (120Ω) to both ends of a RS-485 daisy chain connection. It should be installed at both
ends of the daisy chain. If it is installed in the middle of the chain, the performance in communicating will deteriorate
because it reduces the signal level.
•
Up to 31 card readers or up to 7 fingerprint devices with 24 card readers can be connected with DM-20. (If Xpass set
to master device, fingerprint devices cannot be connected as slave device.)
Termination
resistor (120Ω)
DC
power
GND
+
RS-485 TRX+
RS-485 TRX-
GND
Termination
resistor (120Ω)
Access Controller
Access Controller