The RMX-10101/10102 rack control unit (RCU) is responsible for communicating with and monitoring all aspects of the system.

RCU monitoring and communication tasks include, but are not limited to:
  • Communicating with the PEP to control power sequencing, monitoring the PEP's health, and measuring the input power using the onboard energy meter in the PEP
  • Communicating with the AC PDU to control the ON/OFF state of each outlet bank and to read the AC current through each PDU outlet
  • Monitoring DC PDU voltages and currents
  • Controlling the system fan speed, status LED, optional tower light, and AC and DC power rail ON/OFF status
  • Monitoring system temperature, fan health, and other system health data using connected sensors
  • Maintaining a system log to enable fast debugging
  • Providing a safety interlock output to a source measure unit (SMU)
RCU communication is performed over Ethernet. You can read system health data and control aspects of the system using the NI-ATE Core driver. You can control your rack using the NI-ATE Core driver using the default host name and password, which can be derived from the RCU serial number on the label highlighted in the following figure. This label is removable, and can be relocated if the RCU cannot be easily seen inside the rack.
Figure 1. RCU Serial Number Label
Table 43. Internal RCU DC Output Specifications
Specification Value
Outputs 1
RCU label ITA User Power
Nominal voltage 5 V
Maximum current 1 A
Connector on RCU Molex 1724470002
Pins Pin 1 (+) +5 V
Pin 2 (-) GND
Wire gauge 18-24 AWG for crimp Molex 39000038


  1. Internal RCU DC output
Table 44. Rack Control Unit Measurement Accuracy
Measurement Accuracy Specification
Voltage ±3.0% typical
Current ±3.0% typical
Note Accuracy specifications apply to internal DC power rails present on the RCU. This includes all RCU input and output DC power rails.

RMX-10101/10102 Safety Interlocks

The RMX-10101/10102 RCU can take in four safety interlock inputs that can control the safety interlock output signal to high-voltage equipment without software involvement.

Figure 1. RMX-10101/10102 RCU Safety Interlock Circuitry


Figure 1. RMX-10101/10102 RCU Interlock Input and Output Locations


  1. Interlock inputs 1 and 2
  2. RCU Interlock DIP switch
  3. Interlock inputs 3 and 4 and interlock output
Figure 1. Safety Interlock Inputs 1 and 2 Pinout
  1. Ground
  2. Interlock 1 input
  3. Ground
  4. Interlock 2 input
Figure 1. Safety Interlock Inputs 3, 4 and Outputs Pinout
  1. Ground
  2. Safety Interlock A output
  3. Safety Interlock B output
  4. Interlock 3 input
  5. Interlock 4 input
  6. Ground
Figure 1. RCU Interlock DIP Switch
You can connect up to four safety interlock inputs to the RCU, which you can use to control the safety interlock output signal. These safety interlock input signals can be enabled or disabled by toggling the corresponding DIP switch on the RCU. Enabled signals are passed to the digital gate logic circuit for the rack safety interlocks. The interlock output pins connect when all enabled interlock inputs are pulled low. Each interlock is enabled by the DIP switch which corresponds to its labeled number on the RCU. For example, interlock input 1 is enabled by DIP switch 1.
Note The RCU monitors all safety interlock signals regardless of the state of the DIP switches. Safety interlock signal states can be queried using the NI-ATE Core Driver API.

RMX-10101/10102 Reset Button

The RMX-10101/10102 RCU has a physical reset button that allows you to reset the RCU password and network settings back to their factory default values.

Figure 1. RCU Reset Button

You can perform a reset by pressing and holding down the reset button. The duration the button is held down determines the action taken, as specified in the following table.

Table 45. Reset Button Actions
Hold Duration Action
Less than 5 seconds No action
Between 5 and 15 seconds Resets network port settings to factory default
Between 15 and 25 seconds Resets RCU password to factory default
Greater than 25 seconds No action

RMX-10101/10102 Ethernet Ports

The RMX-10101/10102 has two ethernet ports useful for communication with other hardware and systems.

Figure 1. RMX-10101/10102 Ethernet Ports
  1. Ethernet Port 1
  2. Ethernet Port 2
Table 46. RMX-10101/10102 Ethernet Ports
Port Description
Ethernet Port 1 Gigabit Ethernet port that can support speeds up to 1 Gbps.
Ethernet Port 2 Ethernet port that can support speeds up to 100 Mbps.