NXT 4x4 Module Specifications
8” H x 7” W x 2.75” D
(20.32 cm x 17.78 cm x 6.98 cm)
Size (PC Board):
5.25” H x 3.10” W x 1” D
(13.33 cm x 7.87 cm x 2.54 cm)
Weight (In Enclosure):
2.5 Lbs (1.14 Kgs)
+ 12 VDC nom. (10 - 14 VDC)
250 mA typical
4 general purpose Inputs or
configurable in software to:
- Door Contact Switch
- Request to Exit
- Bond Sensor
4 general purpose Outputs/Relays
1.0 amp (24 VDC max.) dry circuit
Temperature / Humidity:
-40° F to 140° F
(-40° C to 60° C)
0-90% Non Condensing
5 years Memory Retention
Recommended RS-485 Cable Types
Controller Power, Inputs, and Outputs Cable Requirements
Total Run Length
# of Conductors
250 feet [a]
Shortest path [b]
Inputs and Outputs [C]
- To meet CE and C-tick regulations, the length of the controller power line can be no longer than
3 Meters (9.85 feet).
the shortest possible path from earth ground point to PCB. Connect the
earth ground only to the designated pin on the terminal block. This is
important as all transient protection for the unit is made through this
earth ground connection. For unit protection, the earth ground
connection should always be made first.
- Values listed are minimums. Individual input and output devices may have more specific
Lock Output relay may require a heavier gauge of wire depending upon
the current demands of the lock and the length of the lock wiring run.
- Cable resistance causes a drop in voltage at the end of long cable runs. Ensure the appropriate power and current
for your device is available at the device at the end of the cable run. Heavier gauge cable reduces this effect.
- Keri does not recommend hot-plugging a Reader, RIM, or 4x4 into an NXT controller.
Remove power from the controller prior to connecting these devices.