Derivative Action in PID Control Without Noise Problems
Learn what derivative action contributes to a PID loop, why it can amplify measurement noise and setpoint changes, and how filtering, sampling, and staged tests make D tuning safer.
Manufacturer: Bently Nevada
Product No.: 3500/25 149369-01
Country of origin:United States
Product Type: Enhanced Keyphasor Module
Barcode: 8537101190
Payment: T/T, Western Union
Weight: 460g
Dimensions: 119.4 mm x 24.4 mm x 241.8 mm
Shipping port: Xiamen
Warranty: 12 months
The 3500/25, engineered under upgraded spare part assembly component 149369-01, is a half-height, two-channel hardware instrument engineered to distribute precise timing signals to monitoring modules within a 3500 Machinery Protection System rack. The module conditions raw analog pulse waveforms acquired directly from proximity probes or passive magnetic pickups, converting them into digital phase references that signify the precise moment a physical shaft event marker coincides with the field transducer. Operating as a core measurement layer, it tracks once-per-turn or multiple-event-per-turn indices to enable adjacent rack monitors and external diagnostic instruments to compute shaft rotative speed along with vector parameters, including 1X vibration amplitude and phase angle. Formatted with complete backward compatibility to older sub-assemblies, the unit supports multi-channel correlation networks, allowing normal configurations of up to four independent inputs and paired layout mapping up to eight distinct Keyphasor variables across the internal backplane architecture.
| Option Code | Description |
|---|---|
| 3500/25-AXX-BXX | Enhanced Keyphasor Module |
| A: I/O Module Type | |
| 01 | Enhanced Keyphasor I/O Module with Internal Terminations |
| 02 | Enhanced Keyphasor I/O Module with External Terminations |
| 03 | Isolated Keyphasor I/O Module with Internal Terminations |
| 04 | Isolated Keyphasor I/O Module with External Terminations |
| 05 | Internal Barrier Keyphasor I/O Module with Internal Terminations |
| B: Agency Approval Option | |
| 00 | None |
| 01 | CSA/NRTL/C (Class 1, Div 2) |
| 02 | ATEX/IECEx/CSA (Class 1, Zone 2) |
| Spares | |
| 149369-01 | Enhanced Keyphasor Module Main Card (Replaces 125792-01) |
| 125800-01 | Keyphasor I/O Module (Internal Terminations) |
| 126648-01 | Keyphasor I/O Module (External Terminations) |
| 125800-02 | Isolated Keyphasor I/O Module (Internal Terminations) |
| 126648-02 | Isolated Keyphasor I/O Module (External Terminations) |
| 135473-01 | Internal Barrier Keyphasor I/O Module (Internal Terminations) |
| Parameter | Specification |
|---|---|
| Manufacturer | Bently Nevada (Baker Hughes) |
| Model | 3500/25 |
| Part Number | 149369-01 |
| Input Signal Capacity | Accepts up to 2 single-event or multiple-event pulses per module |
| Standard Input Impedance | 21.8 kΩ |
| Isolated Input Impedance | 21.8 kΩ |
| Internal Barrier Impedance | 6.65 kΩ |
| Nominal Power Consumption | 3.2 Watts typical |
| Transducer Supply Voltage | -24 Vdc, 40 mA maximum per channel |
| Maximum Input Frequency | 20 kHz for Proximity Probes | 10 kHz for Magnetic Pickups |
| Maximum Tracked Shaft Speed | 99,999 rpm |
| Minimum Proximity Speed | 1 rpm (0.017 Hz) |
| Minimum Magnetic Pickup Speed | 200 rpm (3.3 Hz) |
| Signal Trigger Range | +10.0 Vdc to -24.0 Vdc |
| Manual Hysteresis Scope | User adjustable from 0.2 to 2.5 Volts |
| Auto-Threshold Frequency | Minimum 1 Hz (60 rpm) |
| Auto-Threshold Amplitude | Minimum 2 Volts peak-to-peak |
| Digital Speed Output Accuracy | Within ±0.01% for speed variables up to 99,999 rpm |
| Phase Accuracy Performance | Max ±1 Celsius shift error up to 10,000 rpm | Max ±6 Celsius shift error up to 99,999 rpm |
| Operating Temperature Range | -30 Celsius to +65 Celsius (-22 Fahrenheit to +150 Fahrenheit) |
| Storage Temperature Scope | -40 Celsius to +85 Celsius (-40 Fahrenheit to +185 Fahrenheit) |
| Operating Humidity Target | 95% non-condensing relative humidity |
| Main Module Card Weight | 0.46 kg (1.0 lb) |
| I/O Module Card Weight | 0.20 kg (0.44 lbs) |
| Main Module Dimensions | 119.4 mm x 24.4 mm x 241.8 mm |
| I/O Module Dimensions | 241.3 mm x 24.4 mm x 99.1 mm |
| Rack Slot Requirements | Requires 1 half-height front slot position |
| Terminal / Connector Pin | Function |
|---|---|
| CH1 / CH2 Coaxial BNC (Front) | Short-circuit protected dynamic unconditioned output for signal capture |
| TRANSDUCERS (PWR / COM / KPH) | Rear terminal connections mapping sensor power, common, and pulse signal |
| SHLD / GND Terminals | Instrumentation shield frame common and chassis earth ground points |
| BUFFERED KPH (BUF1 / BUF2) | Dedicated terminal points providing buffered digital pulse lines to peripherals |
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Returns & Warranty
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| Color pattern |
Silver
|
| Country of origin |
United States
|
| Power source |
DC Power
|