Product Overview
When your control system demands precise and reliable analog output, the Allen-Bradley 1756-OF8K delivers. This ControlLogix analog output module provides eight voltage or current outputs in a compact 20-pin package. Its conformal coating protects against moisture and contaminants, ensuring long-term performance in harsh industrial environments.
As part of the ControlLogix family, the 1756-OF8K integrates seamlessly into your existing architecture. It is engineered for applications that require synchronized sampling, high accuracy, and minimal field calibration. Whether you are upgrading a legacy system or building a new one, the 1756-OF8K offers the performance you need.
Technical Specifications
The 1756-OF8K is built to handle demanding output tasks with precision. Key specifications include:
| Specification |
Value |
| Manufacturer |
Rockwell Automation |
| Brand |
Allen-Bradley |
| Part Number / Catalog No. |
1756-OF8K |
| Series |
ControlLogix |
| Module Type |
Analog Output |
| Number of Pins |
20 Pins |
| Coating |
Conformal Coat |
| Output Ranges |
-10.4 to 10.4 V, 0 to 21 mA |
| Resolution (Current) |
15 bits across 21-650 mA/bit |
| Resolution (Voltage) |
15 bits across 10.4-320 V/bit |
| Operating Temperature |
0 to 60 °C |
| Non-Operating Temperature |
-40 to 85 °C |
| Relative Humidity (Non-Condensing) |
5-95% |
| Operating Vibration |
2g at 10-500 Hz |
| Operating Shock |
30 g |
| Non-Operating Shock |
50 g |
These specifications highlight the module's capability to provide stable, accurate outputs across a wide temperature range. The 15-bit resolution ensures fine control, while the conformal coating adds an extra layer of protection.
Key Features & Benefits
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Synchronized Input Sampling: The 1756-OF8K supports synchronized sampling across all modules in a CIPSynch system, enhancing coordinated control.
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Channel Status and Fault LED Indication: Quickly identify issues with per-channel LEDs, reducing downtime.
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Increased Accuracy, Repeatability, and Stability: Maintains performance over temperature variations, ensuring consistent output.
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CIPSynch-Enabled: Allows timestamping in PTP (Precision Time Protocol) for time-sensitive applications.
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Fast Input Sampling (1 ms): Processes floating point values quickly, enabling rapid response.
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Faster Output Response Times: Improves system throughput and efficiency.
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Increased Precision with 24 Bits of Useable Resolution: Delivers finer control for demanding processes.
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No Need for Field Calibration: Reduces installation and maintenance effort.
Industry Applications
The 1756-OF8K is ideal for applications that require precise analog output signals. Typical uses include:
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Process Control: Regulating valves, dampers, and variable speed drives in chemical, oil and gas, and pharmaceutical plants.
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Discrete Manufacturing: Controlling servo drives and actuators in assembly lines and packaging machinery.
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Power Generation: Managing governor controls and excitation systems in turbines and generators.
For example, in a chemical plant, the 1756-OF8K can adjust flow control valves with high accuracy, maintaining product quality while reducing waste. Its fast response and high resolution make it a cost-effective choice for critical loops.
Installation & Setup Guidance
Installing the 1756-OF8K is straightforward. Follow these steps for a smooth setup:
- Mount the module onto the ControlLogix chassis and secure it in place.
- Connect the removable terminal block (RTB) — either the 1756-TBNH or 1756-TBSH — to the module.
- Wire the output signals to the appropriate terminals, ensuring correct polarity for voltage or current outputs.
- Configure the module in your ControlLogix programming software, selecting the appropriate output range and resolution settings.
- Power up the system and verify channel status via the LED indicators.
Always follow the manufacturer's guidelines for wiring and grounding to avoid electrical interference. The conformal coating protects the module, but proper handling during installation is still essential.
Maintenance & Reliability
The 1756-OF8K is designed for long-term reliability. The conformal coating shields the board from moisture and dust, reducing the risk of corrosion. To maintain optimal performance:
- Periodically inspect the module for dust buildup or physical damage.
- Check that all terminal connections remain tight and secure.
- Monitor channel status LEDs for any faults and address them promptly.
- Keep the module within its specified temperature and humidity ranges.
Routine maintenance is minimal, which lowers total cost of ownership. The module's robust design also minimizes unexpected failures, reducing downtime and repair costs.
Compatibility & Integration
The 1756-OF8K is part of the ControlLogix family and integrates with other ControlLogix modules and controllers. It supports CIPSynch, allowing synchronized operations across multiple modules. The module works with the 1756-TBNH and 1756-TBSH removable terminal blocks, providing flexible wiring options.
For applications requiring precise timing, the CIPSynch capability enables timestamping via PTP, making it suitable for motion control and high-speed processes.
Selection Guide & Purchasing Advice
Before purchasing the 1756-OF8K, consider your application requirements:
- Determine whether you need voltage or current outputs, and verify the required range.
- Check the number of output points needed — this module offers eight.
- Ensure your ControlLogix system supports the module and that you have the correct terminal block.
- If your environment is harsh, the conformal coating is an added benefit.
PLC Source PRO is a reliable supplier of industrial automation parts. We offer genuine Allen-Bradley products and competitive pricing. Contact us to confirm availability and lead times for the 1756-OF8K.