The Bently 3500 system is an online condition monitoring system for rotating machinery launched by Bently Nevada, USA, and the following is a detailed introduction to the system:
System features:
Powerful: It continuously measures and monitors the operating status of rotating and reciprocating machinery, and provides important data for the prevention of unbalance, misalignment, shaft cracks and bearing damage.
High modularity: Each module has a clear division of labor and cooperates with each other, and can be flexibly configured according to actual needs, which is convenient for the expansion and maintenance of the system.
Compliant with industry standards: Fully compliant with the American Petroleum Institute's API670 standard for this type of system, with high reliability and availability.
Strong communication capability: It supports a variety of industry-standard protocols and can interact with other systems such as process control systems and historical data systems.

System composition
Instrument frame: The 3500/05 instrument frame is the physical carrier of the system and can be installed in a variety of ways, with a single power supply or redundant dual power supplies in the frame.
Power Module: The 3500/15 power module powers the frame and its modules, has a self-test function, and indicates whether the output voltage meets the specification via a green "Supply OK" LED on the front panel.
Frame Interface Module: The 3500/20 Frame Interface Module is the primary interface between the 3500 Frame and configuration, display, and condition monitoring software, supporting proprietary protocols that can be modified in the field or remotely.
Transient Data Interface Module: The 3500/22m Transient Data Interface Module combines the functions of a framework interface module and a communication processor, and the main advantage is that it can collect and store transient data.
Monitor modules: including 3500/40m, 3500/42m, 3500/45, 3500/50, 3500/53, 3500/60 and 3500/61, etc., which can monitor and analyze mechanical vibration, displacement, rotational speed, temperature and other parameters.
Relay Modules: The 3500/32 relay module provides four double-pole double-throw relays, and the 3500/34 triple redundant relay module works in conjunction with a dedicated frame interface module as well as three monitor modules to provide a 3-choice 2-vote for the input signal.
Keyphasor Module: The 3500/25 Keyphasor module provides power and terminals to the Keyphasor® sensor, whose signals can be used for measurements such as rotational speed, phase, tracking filtering, and more.
Communication gateway module: The 3500/92 communication gateway module enables the digital transmission of selected status and current value data to other relevant systems.
Display: A 3500/93, 3500/94, or 3500/95 display or 3500 operator display software running on a compatible PC to display system monitoring data and status.

Fields of application
Widely used in electric power, petrochemical, steel, papermaking, metallurgy and other industries, it can monitor and protect gas turbines, steam turbines, compressors, turboexpanders, motors, generators and other rotating and reciprocating machinery.