| 摘要 |
<p>A maintenance interface device for use in a digital, loop-powered process control network includes an interface to either a two-wire input/output port of a field device or to a two-wire communication media, a control logic for determining a simple status of the field device or communication loop, and a display for displaying the simple status. The maintenance interface device may be used for fault analysis to detect whether a field device or a communication loop is operational or nonoperational, powered or unpowered, and generating a valid communication signal or generating an invalid communication signal. The maintenance interface device is adapted to perform simple functionality tests on a plurality of devices in a process control network including a loop controller, a digital control system, an operator console, a workstation, a personal computer, and a bridge to thereby detect the functionality of those devices on a communication wire. The maintenance interface device is self-powered, powered from the device under service, or powered from a communication media such as a bus.</p> |
