1. Multi-Parameter Precision Monitoring

The module supports the connection of two independent proximity probe signals or magnetic pickup sensors, enabling high-accuracy measurement of shaft rotational speed, rotor acceleration, and rotation direction. It includes a peak-hold function that records the highest forward speed, maximum reverse speed, or reverse rotation events. These stored values can be compared with user-defined alarm thresholds, and an automatic alarm is generated when limits are exceeded.
In addition, the module can output conditioned keyphasor signals to the 3500 rack backplane for use by other monitoring and protection modules within the system.

2. Suitable for Harsh Industrial Environments

The module operates reliably across a wide temperature range of –40 °C to +85 °C, making it suitable for demanding industrial sites.
It supports a broad sensor input range of +10.0 V to –24.0 V, with automatic clamping of out-of-range signals to protect internal components.
To adapt to different sensing technologies, the module offers multiple input impedance options, including 20 kΩ for standard applications and 40 kΩ for TMR (Triple Modular Redundant) configurations, ensuring compatibility with various field sensors.

3. High Adaptability and Ease of Maintenance

The module supports Modbus TCP/IP communication, enabling seamless integration into distributed control systems (DCS), SCADA, and industrial monitoring platforms.
Compatibility with the 3500 system requires specific firmware and configuration levels—for example:

3500/20 power module firmware: Version G or later

System configuration software: Version 3.50 or later

Its standardized mechanical and electrical design eliminates the need for external junction boxes during installation, reducing wiring complexity. The modular structure allows quick inspection and replacement, minimizing maintenance downtime and improving long-term system operability.

BENTLY 133827-01 Tachometer I/O Module