Bently Nevada 3500/20 Standard Rack Interface Module

Part Number / Catalog: 3500/20 (Standard Rack Interface Module; variants include 125744-02, 125744-01, 135031-01, 125768-01)

Function: Primary interface of the 3500 Series rack, enabling data collection and rack configuration via proprietary protocol

Communication Protocols: Bently Nevada proprietary over RS232 or RS422; supports external modem (Hayes AT-compatible)

Baud Rate: Up to 38.4 kbaud (auto-baud capable); 14.4 kbaud for modem I/O

Transducer Power Supply: 24 V DC

Input Voltage / Power Requirements: 18–36 V DC; <1 mA DC load on dry contact

I/O Connector: Front-panel RS232/RS422 serial port; rear rack connector for daisy-chaining up to 1200 m (RS422) or 30 m (RS232)

Environmental Limits: Operating: –30 °C to +65 °C; Storage: –40 °C to +85 °C; Humidity: 95% non-condensing

Mounting: Slot 1 of 3500 Series rack (adjacent to power supplies); occupies full-height front slot and full-height rear slot

LED Indicators: Status LEDs for OK and TX/RX activities on front panel

Switch Controls: Front-panel Run/Program switch with locking feature for preventing unauthorized configuration

Environmental Sealing: Conformal-coated PCB for moisture and contaminant protection

Certifications / Compliance: CSA/NRTL/C; meets API 670 rack communication requirements (non-critical path)

Proprietary Serial Communication: Interfaces via RS232 or RS422 to host software for rack configuration and data retrieval.

Run/Program Locking Switch: Prevents unauthorized reconfiguration or enables remote programming without rack removal.

Daisy-Chain Between Racks: RS422 connectivity allows linking multiple racks (up to 1200 m) under a single host connection.

External Modem Support: Hayes AT-compatible modem interface for remote data collection and configuration.

Multi-Mode Operation: Front-panel selection of RS232, RS422, or modem I/O for flexible connectivity.

LED Diagnostics: OK and TX/RX LEDs provide real-time status of module health and communication activity.

Environmental Resilience: Operates in –30 °C to +65 °C and high humidity (95% non-condensing).

Lockable Configuration: Front-panel switch can be locked in RUN or PROGRAM to secure rack settings.

Non-Critical Data Path: RIM function does not impact core monitoring; rack continues protection even if RIM is non-operational.

Rack Configuration & Monitoring: Allows configuration of 3500 rack parameters (alarms, thresholds, I/O mapping) from laptops or workstations.

Remote Data Collection: Supports modem or RS422-based remote access for diagnostics and historical data retrieval from unmanned sites.

Multi-Rack Integration: Enables linking multiple 3500 racks in series for consolidated data acquisition and centralized control.

System Commissioning & Firmware Updates: Provides interface for loading new firmware or configurations into rack modules during commissioning.