Microcomputer Data Acquisition System For Monitoring Underground Instrumentation

A microcomputer controlled data acquisition system has been developed for automatic monitoring of underground instrumentation from a remote location. The system has been used extensively by Spokane Research Center personnel for monitoring rock instrumentation in shafts, drifts, and stopes in hardrock and coal mines, especially where instrument access is limited. Ruggedness was a major consideration in designing the underground portion of the system and it has performed satisfactorily under extreme environmental conditions, including temperatures to 1100 F, 100% humidity, and falling water. The major advantage of the system is that it multiplexes the data from 16 channels through a single twisted pair cable to the receiver, significantly reducing cabling requirements. This receiving station can be as far as 8,000 ft from the instruments without the addition of line drivers. The receiver maintains a data buffer with the latest scans, which is periodical 1 y accessed by a micro- computer, either locally or through a modem, that automatically records and reduces the data. Utilities allow on-site plotting of data and uploading of data to mainframe computers.