Product Overview
The Allen-Bradley 1769-OF8C is an analog output module from the CompactLogix series, designed for precise current output control in industrial automation systems. With eight single-ended output channels configurable for 0-20 mA or 4-20 mA, this module delivers reliable signal transmission to final control elements (FCEs) such as modulating valves, VFDs, and positioners. Its compact single-width design integrates seamlessly into 1769 and 1768 CompactLogix systems as well as MicroLogix 1500 controllers.
Built for demanding applications, the 1769-OF8C features a 16-bit resolution, a fast 5 ms conversion rate, and comprehensive diagnostic capabilities. The module's open and short-circuit protection, along with its overvoltage protection, ensures robust operation in critical control loops. Whether you're upgrading existing systems or building new ones, the 1769-OF8C offers the performance and reliability expected from Allen-Bradley.
Technical Specifications
| Specification |
Details |
| Series |
1769 Compact I/O |
| Module Type |
Analog Output Module |
| Part Number |
1769-OF8C |
| Brand |
Allen-Bradley |
| Manufacturer |
Rockwell Automation |
| Number of Outputs |
8 (current outputs) |
| Output Current |
0-20 mA / 4-20 mA |
| Output Current Range |
0-21 mA; 3.2 mA - 21 mA |
| Resolution |
16 bit |
| Conversion Rate (all channels) |
max. 5 ms |
| Overall Accuracy |
±0.35% full scale at 25°C |
| Open and Short-Circuit Protection |
Yes |
| Maximum Short-Circuit Current |
21 mA |
| Current Draw |
145 mA at 5VDC; 185 mA at 24V dc |
| Channel Diagnostics |
Over/under-range, wire broken, load resistance high |
| Enclosure |
None |
| Product Line |
CompactLogix |
| Input Type |
Output Current |
| Communication Cable |
8 Point |
| Shipping Weight |
2 pounds |
| Shipping Dimensions |
8 x 8 x 5 inches |
| Converter Type |
Delta Sigma |
| Outputs |
8 single-ended |
| Replacement Door Part Number |
1769-RD |
| Wire Type |
Copper-90 degrees |
| Solid Wire Size |
22 to 14 AWG |
| Stranded Wire Size |
22 to 16 AWG |
| Heat Dissipation |
2.69 Watts |
| UPC |
10662468861622 |
The 1769-OF8C achieves a step response to 63% output in less than 2.9 ms, making it suitable for fast-acting control loops. Its maximum inductive load is 0.1 mH, and the resistive load range is 0 to 500 ohms including wire resistance. The module operates without field calibration and dissipates only 2.69 watts of heat, contributing to energy-efficient panel design.
Industry Applications
The 1769-OF8C excels in applications requiring precise analog current output. Typical uses include:
-
Process Control: Driving modulating control valves and positioners in chemical, oil, and gas plants.
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Variable Frequency Drives (VFDs): Supplying speed or torque reference signals to VFDs for motor control.
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Data Acquisition: Sending signals to panel meters, data loggers, and signal splitters for monitoring and recording.
In a typical PID control loop, the 1769-OF8C interfaces directly with the processor's embedded PID algorithm, ensuring accurate and responsive control of final elements.
Installation & Setup Guidance
Mount the 1769-OF8C in a 1769 or 1768 CompactLogix chassis as local or expansion I/O. The module is single-width and installs easily. Use the integral removable terminal block with finger-safe protection for wiring. Route wires from beneath the module to the terminals for a clean installation. Use copper wire rated for 90°C, with solid wire sizes 22-14 AWG or stranded wire sizes 22-16 AWG. Ensure the external power supply provides 24V DC, as required by the module.
Because the module has no enclosure, install it in a suitable industrial cabinet to protect against dust, moisture, and accidental contact. The operating temperature range is 0 to 60°C, so ensure adequate ventilation.
Maintenance & Reliability
Regularly inspect the terminal block connections for tightness and signs of corrosion. The module's LED indicator provides status: green indicates normal operation, while a fault condition (e.g., open loop) triggers a warning. The module performs self-diagnostics for over/under-range, wire breaks, and high load resistance. With no field calibration required, maintenance is minimal. The 1769-OF8C's robust protection features—overcurrent, overvoltage, open and short-circuit—minimize downtime and extend service life.
Compatibility & Integration
The 1769-OF8C is compatible with 1769 and some 1768 CompactLogix controllers, as well as MicroLogix 1500 controllers. It integrates as local I/O or expansion I/O. The module uses an 8-point communication cable and supports up to 8 simultaneous analog output channels. Its Delta Sigma converter type ensures high accuracy and stability.
Selection Guide & Purchasing Advice
Before purchasing, verify your controller compatibility and required output range (0-20 mA or 4-20 mA). Consider the number of channels needed and ensure your power supply meets the current draw specifications. The 1769-OF8C comes with a replacement door part number 1769-RD, which may be useful for maintenance. For reliable sourcing, PLC Source PRO offers genuine Allen-Bradley 1769-OF8C modules with competitive pricing and fast shipping.