Patent ID: 8392058
Filing Date: 2013-03-05
Classification: G05B,H04L

Abstract:
1. An electrical communications circuit comprising a power supply, a trunk section, a spur section, isolation means disposed between the trunk section and the spur section, diagnostics apparatus connected to the trunk section and a field device connected to the spur section, in which the field device is adapted to send data signals over the communications circuit, which data signals comprise one or more core functions, one or more secondary functions and a transmission sequence, in which under normal operating parameters the communications circuit comprises physical layer attributes within pre-determined thresholds, in which a spur diagnostics module is connected to the spur section and is adapted to monitor electrical characteristics of the spur section, in which the spur diagnostics module comprises interference means adapted to make a change to a physical layer attribute of the trunk section such that it breaches one of said ore-determined thresholds and/or to make a change to a secondary function or the transmission sequence of the data signals sent thereon, in which the diagnostics apparatus is adapted to detect said change, and in which the spur diagnostics module is adapted to activate said interference means when it detects one or more pre-determined electrical events in the spur section.