Molunghi landslide monitoring, Italy

Study and monitoring of Molunghi landslide The monitoring project of Molunghi landslide is the result of the cooperation between the Comune di Calice al Cornoviglio and the Road Department of La Spezia Province and it is began in consequence of the instability of both the provincial street and part of Monlunghi di Mezzo inhabitat during […]

FAQ#116 – How do I configure a WR-Log digital node to read RS485 Sisgeo TIMED sensors?

Sisgeo digital instruments can operate in two powering modes: TIMED or ALWAYS-ON (for more information see F.A.Q.#094).A string of mixed instruments consisting of TIMED gauges and ALWAYS-ON gauges cannot work.The first thing to do is therefore to check that ALL connected instruments in your array are set to TIMED mode.You can check the powering mode […]

FAQ#111 – Why I cannot read correctly my 4-20mA current loop gauge?

It could be a problem connected to the power supply given by the readout or logger. When the power supply is in the current loop (2-wire gauge) it is necessary to consider the effect of voltage drop across the shunt resistor on the voltage applied to the gauge. For example, suppose a 4-20mA gauge requires […]

FAQ#095 – How long does a chain of digital sensors take to be read?

It mainly depends from the powering mode of the gauges (refer to FAQ#094 for the description of the powering modes). AN EXAMPLE WILL BETTER CLARIFY THE ANSWER. In a batch of 240 gauges, unless otherwise requested by the Customer, the addresses are settled from #001 up to #240. In a borehole is installed a chain of 30 […]

FAQ#087 – Could the IPI, BH Profile and DEX probes have problems in frozen water?

Sisgeo suggest that frozen water within the inclinometer casings is to be avoided due to following reasons: – Ice within the casing will affect functionality of the systems by blocking the individual probes;– Mechanical damages can occur to the probes, but also to the inclinometer casing due to the expansion of frozen water In any […]

FAQ#077 – Which are the maximum cable lengths from instrument to datalogger?

The cable lengths depend from many factors, first of all installation and cable protections (screen, earth, etc…). Assuming that instruments are installed in a workmanlike, for the maximum cable lengths should be followed the next suggestions: DIGITAL INSTRUMENTS: see FAQ#73 ANALOGUE INSTRUMENTS: see both downloadable documents.

FAQ#076 – Why it is necessary add a termination resistor to the last digitized sensor of each RS-485 chain?

All SISGEO digitized instruments (IPIs, Tiltmeters, H-Level…) use the RS-485 serial communication protocol The RS485 protocol contemplate a termination resistor. The recommended chain connection is point-to-point (multidropped) nodes as a bus mode (line). Star, ring or multiply network connection are not recommended. SISGEO dataloggers has already a termination resistor assembled (typically 120Ω). On the opposite […]

FAQ#074 – Which kind of datalogger is necessary to read a SISGEO digital sensors?

The sensors are read connecting the end cable to a Modbus Master unit (i.e. OMNIAlog or miniOMNIAlog) with RS-485 interface (DCE, Half duplex, no Echo) able to manage communication with SISGEO Modbus RTU communication protocol. SISGEO’s communication protocol is available for the release upon request. The power [W] of power supply must be chosen according […]

FAQ#073 – Which is the maximum number of digitized sensors (RS-485, Modbus), the maximum number of chains and the maximum length of cable in a RS-485 network?

Last update: October 2021 All the SISGEO digitized sensors utilize a RS485 interface with Modbus protocol. 1.The maximum number of digitized sensors in a RS-485 network are 247 (theoretical) 2.The maximum number of digitized sensors chains that is possible to connect to Modbus master unit (as OMNIAlog or miniOMNIAlog) are 4. 3. About the maximum […]