Communication Wiring - HID Mercury LP1502 Installations And Specifications

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2.5 Input power, cabinet tamper and UPS fault input wiring
The LP1502 requires 12 to 24 V DC power. Locate power source as close to the unit as possible.
Connect power with minimum of 18 AWG wire. Connect the GND signal to earth ground in ONE
LOCATION within the system! Multiple earth ground connections may cause ground loop problems and is
not advised.
Observe POLARITY on 12 to 24 V DC input!
There are two dedicated inputs for cabinet tamper and UPS fault monitoring. Normal (safe) condition is a
closed contact. If these inputs are not used, install a jumper wire.

2.6 Communication wiring

The LP1502 controller communicates with the host via the on-board Ethernet 10-BaseT/100Base-TX port,
and/or the USB port (2.0) with an optional USB to Ethernet adapter.
The serial I/O device communication port (TB3) is a 2-wire RS-485 interface which can be used to connect
additional I/O panels. The interface allows multi-drop communication on a single bus of up to 4,000 feet
(1,219 m). Use 1-twisted pair with drain wire and shield, 120Ω impedance, 24 AWG, 4,000 feet. (1,219 m)
maximum for communication.
Caution: Install the termination jumper ONLY on the panel at each end of the RS-485 bus. Failure to do so will
compromise the proper operation of the communication channel.
PLT-05244, A.3 11
HID Mercury™ LP1502 Controller
Installation and Specifications
June 2021