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 […]

Bridge Monitoring on Dnieper River, Kiev, Ukraine

Railway – highway stream crossing with double track railway line and six traffic lanes (three lanes in one direction) across Dnieper River in Kiev City. Total length of the bridge is 1.100 meters. End-of-work scheduled term: end of 2009. Estimated traffic load is more than 300.000 vehicles per day. Load cells are used for monitoring […]

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 […]

Egnatia Odos Road – Athens, Greece

Egnatia Motorway was designed to the specifications of the Trans-European road network. Across Epirus and Northern Greece from Igoumenitsa to Evros, Egnatia Motorway is one of the largest road construction projects in Europe, 670 kilometres long and 24.5 metres wide.The realisation of this motorway requires the construction of: 50 road interchanges; 350 entrance / exit […]

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 […]

Puerto Cabello-La Encrucujada railway project, Venezuela

The section Puerto Cabello – La Encrucijada (Cagua) is part of a more multi-modal and articulated transportation network of freights and passengers. During the first stage of works, the above said section will connect the principal port of the country (Puerto Cabello) to the industrial, agricultural and food poles of Valencia and Maracay. The next […]