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If you plan on using the intercom’s card reader for access (without an Openpath Smart Reader), run the W0, W1 and GND signals from the intercom to a Wiegand input on the 4-Door Controller or any I/O pair on the 4-Port, 8-Port, or 16 I/O Elevator Board. The intercom power supply and the ACU power supply should share a common ground. See How to wire Wiegand devices to Core Series hardware.
If you are installing an Openpath Smart Reader at the same entry as the intercom, connect the Wiegand W0 and W1 signals from the intercom directly to the WD0 (Green) and WD1 (White) wires on the Smart Reader pigtail.
The REX signal can also pass back to the ACU in the same cable bundle as the Smart Reader wires if there is a spare twisted pair available. Run power for the intercom separately, since it may require heavier gauge wires.
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