Remote monitor and control system

In a remote monitoring and control system of the type including an operations console at a central control point, a wire center unit located remote from the operations console at a location at which wire pairs for a geographic area are concentrated, and a plurality of monitored switching units in the area to be remotely monitored and controlled from the central control point, and wherein each switching unit includes a switchable connection arrangement and is connected to the wire center by a control wire pair comprising a tip and ring wire in predetermined connection order, the connection being provided so that the wire center may monitor and control the switching unit, and wherein a communications path extends between the wire center and the central control point, an improved wire center unit comprising a plurality of interconnected modules including:

• at least one line select module for selecting a switching unit wire pair from among a plurality of pairs extending from switching units and connected to the line select module,
• a line switch decoder module for sensing connection arrangement conditions present at a selected switching unit and for converting sensed conditions into a binary code, and independently for providing a control signal to the selected switching unit via the line select module to change the connection arrangement thereof,
• a communications module connected to the communications path for decoding commands received from the operations console and for encoding responses from the wire center unit sent to the operations console, and
• programmable digital microcomputer means for controlling all operations of the wire center unit with reference to a said switching unit in accordance with a series of instructions stored in a read only program memory associated with the digital microcomputer means and in accordance with commands received via the communications module concerning the said switching unit and connection arrangement conditions monitored at the said switching unit via the line switch decoder module and for providing responses to the operations console via the communications module.