The ETX-1640x includes an interlock circuit that you can configure to prevent devices from outputting hazardous voltage, with the exception of controlled conditions.

The interlock circuit collects hardware inputs that indicate whether they are Open or Closed. The hardware inputs are combined to determine the overall state of the interlock circuit, which is also either Open or Closed. The overall interlock circuit output allows or disallows output from controlled devices.

The interlock circuit has four distinct hardware input conditions that control the hardware state:
  • Adapter Detect
  • HV Enable
  • User Interlock
  • Door Interlock

By default, the interlock circuit on the ETX-1640x responds to three of these input conditions before transitioning from the default Open state to the Closed state. The ETX-1640x includes an optional fourth configurable input, called the User Interlock, which you can add to the interlock circuit if required.

You can configure the interlock circuit to ignore the state of certain inputs depending on the state of the RCU Interlock DIP switches. This configuration allows the interlock circuit to treat the inputs as Closed even if they are Open for the purposes of controlling the overall circuit output. This is useful when specific inputs are not in use.

Table 43. Requirements for Closing Interlocks
Condition Name Interlock Number CLOSED Condition Interlock Control Pins on the Mass Interconnect
Adapter Detect 1 The Adapeter_Detect+ pin is pulled low (for example, through Adapter_Detect-).

J1 A33 (Adapter_Detect+)

J1 A34 (Adapter_Detect-)
HV Enable 2 The HV_Enable+ pin is pulled low (for example, through HV_Enable-).

J1 C33 (HV_Enable+)

J1 C34 (HV_Enable-)
User Interlock 3 Terminal Block Relay TB25 is closed. N/A
Door Interlock 4 The front door, rear door, and both side panels are closed. N/A

Use the RCU Interlock DIP switches to configure which of these inputs are used to determine the Open or Closed state of the interlock circuit. Each switch can independently activate or deactivate whether its corresponding input (interlock number 1-4) controls the Open or Closed state of the interlock circuit. If the switch is Closed, the system tracks the input, and the overall interlock circuit considers its state. The state of an input is considered Closed when evaluating the overall interlock circuit state if its corresponding DIP switch is in the Open position. This applies regardless of whether the input is in the Open or Closed state. If all four DIP switches are Off, the interlock circuit output is Closed.

The output of the interlock circuit is available on the TB16, TB17, and TB18 relays on the terminal block connections. Refer to DIP Switches for more information. The state of these relays follows the state of the overall interlock circuit.