3500/40M 125680-01 is the standard Proximitor I/O Module with internal terminations for the Bently Nevada 3500/40M monitor. It provides the rear signal interface for four proximity-transducer channels.

The module occupies one rear full-height slot behind the monitor and keeps field wiring at the rack. Its non-barrier construction follows the standard 3500/40M I/O environmental range.

• Provides internal rack termination for four 3500/40M proximity-transducer inputs.
• Supplies -24 V DC transducer power through the matched monitoring loop.
• Uses the standard 10 kΩ input impedance specified for non-barrier I/O.
• Maintains direct pairing with the associated full-height 3500/40M monitor.
• Supports the monitor measurement modes selected through rack configuration.

• Designed for the Bently Nevada 3500 machinery-protection rack and the 3500/40M four-channel monitor arrangement.
• Works with compatible Bently Nevada proximity transducers selected for radial vibration, position, differential expansion, eccentricity or REBAM measurement.
• Channel pairs 1–2 and 3–4 are configured by the rack configuration software; each pair uses one supported measurement function.
• Standard and barrier rear I/O modules have different operating ranges and must be matched to the installed application.
• External-termination I/O requires the separately selected termination blocks and cables; it is not interchangeable with internal termination hardware without an installation review.

• Replace 3500/40M 125680-01 only after documenting the existing field-terminal assignments and the monitor slot.
• Keep the internal-termination arrangement; an external-termination conversion needs the corresponding block and cable design.
• Confirm that the replacement remains the non-barrier standard I/O version.
• De-energize the rack and follow the site machinery-protection procedure before withdrawing rear I/O hardware.
• Validate transducer power, channel polarity and alarm response after installation.