FAQ#075 – What parameters are saved in SISGEO digital sensors? What information must the Customer provide when ordering?


All SISGEO digital sensors (e.g. IPI, BH Profile, MD Profile, LT Inclibus, Tilt-meter, RDS, H-Level, etc.) use the Modbus communication protocol over RS-485 serial.

SISGEO digital sensors are connected to each other with a single signal cable. The parameters that are configured at the factory for each digital sensor are as follows:

  1. Calibration parameters derived from the Calibration Report of each sensor
  2. Serial number that uniquely identifies each instrument
  3. RS-485 address. Each digital sensor also has an address on a label on the cable or printed on the gauge body. The address indicates in the instrument string the name of the instrument the readout is calling. If there are two different instruments with the same address in a sensor string, this obviously leads to problems, so care must be taken not to have two identical addresses in the same physical sensor string.
  4. Type of power supply (more information available in FAQ#094)
    1. ALWAYS-ON (all digital sensors switched on together). Fastest solution, but with a peak in power consumption.
    2. TIMED (sensors are powered and switched on one at a time). It takes a little longer to read the chain than the ‘always on’ mode, but the peak power consumption is lower.
  5. Unit of measurement, defined during calibration. Each instrument type has one unit of measurement by default, but the customer can choose a different one for his own needs. For example, some tilt sensors have sine(angle) as the unit of measurement, but you can choose to have the values output in degrees, mm/m, radians, or other units.

Upon confirmation of the order, the Customer shall inform Sisgeo about

  • addresses to be used for each instrument
  • power supply mode to be used
  • desired unit of measurement (the default unit will be utilized without information)
  • values of termination resistors (for more information refer to FAQ#076)

For further clarification of the information required when ordering, please contact your Sales Representative.