Nexus 2 - Hardware Description

Nexus 2

The Nexus 2 is a rugged and compact network appliance that is designed for use in industrial applications. It can be mounted horizontally or vertically (wall-mount) and the orientation will not affect its function. For best performance, the Nexus 2 should be mounted so that ambient or flowing air can pass across the heatsink fins. As there are no fans, the Nexus 2 does not have an active cooling system and convection cooling is the primary means of removing heat from the device.

The Nexus 2 is expandable in function through the use of USB dongles and adapters. Please consult the applicable Help Guides or contact Clarus Networks for expansion options.

Detailed Port Descriptions

Port Specification

Power Specification

Power Button and Power States

The Nexus 2 has 3 power states: On, Off and Sleep. The Sleep state is not widely used.

To turn the device On: Press the power button once.

To turn the device Off: Hold the power button for 5 seconds. Wait a minimum of 5 seconds before turning the device On again.

To Reboot the device: There is no physical reboot/reset button on Nexus 2. To reboot/restart the Nexus 2 from the On state, Press and hold the power button for 5 seconds, release the power button. wait 5 seconds, then press the power button once.

The following table details the procedure to switch between each of the three power states.

LED Indicators

The Nexus 2 has 3 LEDs to indicate the power state and function of the device.

Power Protection Reset and Cycling Behavior

The Nexus 2 has an integrated Power Protection circuit that protects the device from intermittent and inconsistent power. This circuit requires removing power for a certain ‘lock-out’ period of time so that the Nexus 2 may reset and recognize that external power has been reapplied.

Clarus Networks recommends always using a dedicated Uninterruptable Power Supply (UPS) Battery Backup system for any Nexus 2 installation that may see sudden, momentary power resets.

Power Cycling Example Behavior Diagrams

Users may notice different behavior when cycling DC and AC power to the Nexus 2. The behavior can be explained in two ways:

1. The Nexus 2 has a few product variations with slightly different startup power behavior. These include differences in power management implementation based on manufacture date [which is not a parameter trackable by Device ID (DID)] and processor differences. Both variables change the power consumption and power lock-out time constant.

2. Different use cases have associated power hold-up and power lock-out times. The following diagrams show the power cycling behavior and timing in 2 different cases: cycling DC power and cycling AC power.

For all variants of the device, following these guidelines will have predictable behavior:

For consistent DC power restart behavior, DC power must be removed for 3 seconds before being reapplied.

For consistent AC power restart behavior, AC power must be removed for 30 seconds before being reapplied.

Power Cycling Behavior Explained

Disconnecting DC power from Nexus 2

• Cuts the DC voltage to Nexus 2

• Nexus 2 runs from internal DC capacitance

• Nexus 2 internal DC capacitance drains within 3 seconds

Disconnecting AC/DC adapter from AC Power Source (Mains)

• AC/DC Adapter capacitance maintains +12VDC

• Nexus 2 runs from internal DC capacitance and external AC/DC adapter capacitance

• Nexus 2 drains internal and external capacitance within 30 seconds

Quickly reconnecting AC/DC adapter after disconnecting recharges the Nexus 2 and AC/DC adapter internal capacitance banks and extends the drain / power lock-out time up to 60 seconds.

Mechanical

Mounting Features

2x threading mounting holes: M3 x 0.5mm Depth: 4.5mm

Environmental

Operating temperature range
Up to -10°C to +50°C {Extended temperature range models available, when used with power supply}

Relative humidity
5% – 95% non-condensing

MIL STD 810G compliant

• Vibration test:
  IEC TR 60721-4-7:2001+A1:03, Class 7M1, test method IEC 60068-2-64 (up to 2 KHz , 3 axis)

• Shock test:
  IEC TR 60721-4-7:2001+A1:03, Class 7M1, test method IEC 60068-2-27 (15g , 6 directions)