System and method for hitless monitoring access of a communications circuit

A system for monitoring a communications circuit, comprising:

• a first impedance element configured to be connected to a first communications circuit line of the communications circuit when the communications circuit is established;
• a second impedance element configured to be connected to a second communications circuit line of the communications circuit when the communications circuit is established, wherein the first and second impedance elements are configured to be switchably connected to form a differential impedance across the communications circuit, and wherein the differential impedance formed by the first and second impedance elements causes communication devices communicating via the communications circuit to adapt to a presence of the differential impedance;
• a monitor access element, wherein the first and second impedance elements are configured to be switchably disconnected from the monitor access element, and wherein the monitor access element is configured to be a virtual differential zero impedance;
• and
• a communications circuit monitor, wherein the communications circuit monitor is configured to be connected to the monitor access element, and
• wherein to monitor the communications circuit, the first and second impedance elements are configured to be switchably connected to the monitor access element, and the first impedance element is configured to be switchably disconnected from the second impedance element, thereby connecting the communications circuit monitor to the communications circuit with an absence of disruption to data communication within the communications circuit.

A method for monitoring a communications circuit, comprising the steps of:

• connecting an impedance element to the communications circuit when the communications circuit is established, wherein the impedance element causes communication devices communicating via the communications circuit to adapt to a presence of the impedance element;
• switchably connecting the impedance element to a reference ground point;
• switchably disconnecting the impedance element from a monitor access element, wherein the monitor access element is configured to be a virtual reference ground point;
• connecting a communications circuit monitor to the monitor access element;
• switchably connecting the impedance element to the monitor access element;
• switchably disconnecting the impedance element from the reference ground point, thereby connecting the communications circuit monitor to the communications circuit with an absence of disruption to data communication within the communications circuit;
• and
• monitoring the communications circuit using the communications circuit monitor.

A method for monitoring a communications circuit, comprising the steps of:

• connecting a first impedance element to a first communications circuit line of the communications circuit and a second impedance element to a second communications circuit line of the communications circuit when the communications circuit is established;
• switchably connecting the first and second impedance elements to form a differential impedance across the communications circuit, wherein the differential impedance formed by the first and second impedance elements causes communication devices communicating via the communications circuit to adapt to a presence of the differential impedance;
• switchably disconnecting the first and second impedance elements from a monitor access element, wherein the monitor access element is configured to be a virtual differential zero impedance;
• connecting a communications circuit monitor to the monitor access element;
• switchably connecting the first and second impedance elements to the monitor access element;
• switchably disconnecting the first impedance element from the second impedance element, thereby connecting the communications circuit monitor to the communications circuit with an absence of disruption to data communication within the communications circuit;
• and
• monitoring the communications circuit using the communications circuit monitor.

A method for connecting and disconnecting a selected load to/from a communications circuit, comprising the steps of:

• connecting the selected load to the communications circuit with an absence of disruption to data communication within the communications circuit, by substituting the selected load for an equivalent load,
• wherein the equivalent load is configured to be connected to the communications circuit at the time the communications circuit is established, and
• wherein the equivalent load causes communication devices communicating via the communications circuit to adapt to a presence of the equivalent load;
• and
• disconnecting the selected load from the communications circuit with the absence of disruption to data communication within the communications circuit, by substituting the equivalent load for the selected load.