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Addressable Vibrating Wire Interface | Model 8020-30

  • Model 4150 Addressable Strain Gage, shown on soil nail.
  • Closeup of Model 4150 Addressable Strain Gage, shown on soil nail, with Model 4150-1 protective cover plate removed.
  • Model 4675 High Sensitivity Settlement System with Model 8020-30 Addressable Interface, on a concrete wall with exaggerated settlement to illustrate change in elevation.
Model 8020-30

The Model 8020-30 Addressable Interface is designed to “daisy-chain” vibrating wire sensors on a single 4-conductor cable, using the Modbus® RTU protocol over an RS-485 connection. It is particularly useful for reducing cable runs in multipoint systems, incremental extensometers, and for applications where many sensor cables might compromise a grout or cement bond, e.g. on a soil nail. The system features state of the art signal conditioning and digital addressing to provide a measuring system comprising of up to 100 sensors along one common cable (the maximum number of sensors is determined by overall cable length and power supply: please contact GEOKON for more information). Readout is achieved with the FPC-2 Field PC, 8600 Series Dataloggers or via a PC application.


400 Hz to 5000 Hz
Frequency Trueness
0.082 Hz
Frequency Precision
0.146 Hz (99% Confidence Interval)
Frequency Resolution
0.002 Hz
Freq. Measurement Duration
360 mS
Modbus RTU over RS-485 @ 115200 baud
Temperature Range
–40°C to +80°C

Please Note: GEOKON maintains an ongoing policy of design review and reserves the right to amend products and specifications without notice. Various instruments are discontinued over time and replaced with new, updated models.

Modbus® is a registered trademark of SCHNEIDER ELECTRIC USA, INC. All other trademarks are the property of their respective owners.