Overview
The Allen-Bradley 1756-OF6VI is a ControlLogix 6-point isolated analog voltage output module designed for precision analog signal generation in industrial automation systems. As part of Rockwell Automation’s ControlLogix platform, this module occupies a single slot in the ControlLogix chassis and provides six individually isolated voltage output channels capable of generating ±10 VDC signals for valve drivers, proportional controls, and process instrumentation.
Key Features
- Six Isolated Voltage Outputs: Each channel independently isolated to 250V (basic insulation) for noise immunity and fault containment.
- Precision Resolution: 14-bit output resolution across 21V (1.3 mV) and 13-bit resolution across 10.5V plus sign bit for accurate process control.
- Superior Accuracy: Calibration accuracy better than 0.1% of range with re-calibration required only after 6 months of operation.
- Electronic Protection: Overvoltage protection rated at 24 VDC and current-limited short-circuit protection on all outputs.
- Fast Settling Time: Output settling to 95% of final value in less than 2 milliseconds with resistive loads.
- Flexible Data Formats: Supports integer mode and IEEE 32-bit floating-point data formats with on-board alarming and scaling to engineering units.
Technical Specifications
- Output Channels: 6 individually isolated
- Output Signal Range: ±10 VDC (±10.5V overall)
- Resolution: 14 bits across 21V (1.3 mV); 13 bits across 10.5V + sign bit
- Output Impedance: 1 Ohm
- Load Capability: Loads rated >1000 Ω at 10 mA minimum
- Settling Time: <2 ms to 95% of final value (resistive loads)
- Calibration Accuracy: Better than 0.1% of range
- Calibration Interval: 6 months
- Module Error Margin: 0.5% overall
- Isolation Voltage: 250V (basic insulation, tested at 1350V AC for 2 seconds channel-to-backplane and channel-to-channel)
- Backplane Current Draw: 175 mA @ 24V DC; 250 mA @ 5.1V DC
- Maximum Backplane Power: 5.5 Watts
- Power Dissipation: 4.85W; Thermal Dissipation: 16.54 BTU/hr
- Operating Temperature Range: 0°C to 60°C (5–95% non-condensing humidity)
- Environmental Shock: 30G operational shock; 2G vibration (10–500 Hz)
- Temperature Code: T4A (North America); IEC T4
- Module Scan Time: 25 ms (floating point); 10 ms (integer)
- Certifications: CE, CSA, KC, MARINE, NRTL, RCM, UL
- Series: Series A
Typical Applications
The 1756-OF6VI is used in process control systems requiring multiple isolated analog outputs, including:
- Proportional valve control in hydraulic and pneumatic systems
- Variable frequency drive signal generation
- Analog sensor excitation and signal conditioning
- Motion control command outputs
- Data acquisition and distributed I/O networks
- Batch processing and continuous manufacturing environments
Compatibility & Replacements
The 1756-OF6VI is compatible with all ControlLogix 5580, CompactLogix 5380, and GuardLogix 5580 chassis systems supporting 1756-series modules. The module integrates directly into Studio 5000 Logix Designer environments. The product was discontinued by Rockwell Automation as of March 31, 2017; Rockwell designates the 1756-OF6CI (current-output version) as the functional replacement for new designs, though the 1756-OF6VI remains a drop-in replacement in existing systems. Terminal block connector housings (1756-TBNH or 1756-TBSH) are available for external wiring connections.
