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B&R BRADOL-0
Product Type: Analog Reference Voltage Supply Module
Product Introduction:
The B&R BRADOL-0 is a precision analog reference voltage source module for the B&R X20 bus system. It provides a stable, low-noise reference voltage for all analog input and output modules in the X20 system, ensuring high measurement accuracy and signal integrity across the entire analog I/O chain.
Detailed content
Technical Specifications:
| Parameter | Value |
|---|---|
| Reference Voltage Output | +10.000V DC / -10.000V DC |
| Voltage Accuracy | ±0.1% (typical), ±0.2% (max over temperature) |
| Temperature Drift | ≤ 10 ppm/°C |
| Output Current Capability | ±10 mA (max per rail) |
| Noise (RMS) | ≤ 50 µV (0.1 Hz to 10 Hz) |
| Supply Voltage | 24V DC (via X20 bus) |
| Operation Temperature | -25°C to +70°C |
| Protection Class | IP20 |
| Dimensions (W×H×D) | 22.5 mm × 90 mm × 120 mm |
| Weight | Approx. 140 g |
| Conformity | CE, UL, CSA |
Functional Features:
- Provides dual-rail precision reference voltage: +10V and -10V DC
- Ultra-low noise output (≤ 50 µV RMS) for high-accuracy analog measurements
- Low temperature drift (≤ 10 ppm/°C) ensures stability across the full operating range
- Current capability of ±10 mA sufficient to power multiple analog modules simultaneously
- Auto-calibration capability via B&R Automation Studio software
- Diagnostic LED indicating reference voltage status and fault conditions
Structural Characteristics:
- Snap-in DIN rail TS35 mounting
- Spring-loaded push-in terminals for 0.14 mm² to 2.5 mm² wire
- Housing material: glass-fiber reinforced polyamide (PA66-GF30)
- Dedicated reference voltage bus connector on the rear for distribution to other X20 analog modules
Working Principle:
The BRADOL-0 contains a precision bandgap voltage reference circuit with temperature compensation. The internal reference generates a stable +10V DC rail, which is then inverted to produce the -10V DC rail using a precision voltage inverter. Both rails are buffered by low-noise operational amplifiers to deliver clean, stable voltage to all connected analog modules via the X20 reference bus. The module draws its operating power from the 24V DC X20 bus.
Advantages & Highlights:
- Exceptional voltage stability with ±0.1% accuracy — critical for high-precision measurement applications
- Dual-rail output (+10V/-10V) supports both unipolar and bipolar analog signals
- Ultra-low noise floor ensures 16-bit ADC/DAC modules achieve full resolution
- Single module powers the entire analog I/O chain — eliminates need for external references
- Compact form factor saves cabinet space
Applicable Industries:
- Precision measurement and test equipment
- Laboratory automation
- Pharmaceutical manufacturing (dosing, weighing)
- Semiconductor equipment
- Food and beverage processing (flow, level, temperature measurement)
Installation Requirements:
- Mount on DIN rail TS35 adjacent to analog I/O modules for short reference bus runs
- Connect the reference voltage bus cable from BRADOL-0 to the first analog module in the chain (daisy-chain topology)
- Ensure 24V DC bus power is stable and within 20.4V to 28.8V DC
- Keep reference bus cables away from high-power cables (minimum 50 mm separation) to avoid induced noise
Usage Precautions:
- Do not short-circuit the +10V or -10V reference outputs — this will damage the internal reference circuit
- Do not connect external loads exceeding ±10 mA to the reference outputs
- Do not disconnect the reference bus while analog modules are powered — this causes measurement drift
- Verify reference voltage with a calibrated multimeter before commissioning
- Replace the module immediately if the diagnostic LED indicates a reference fault
