Product Introduction
The Allen-Bradley 1756-OF6CI is a ControlLogix isolated analog output module designed for current loop applications. This module provides six individually isolated current outputs, each with 13-bit resolution across 21 mA (2.7 µA per step). It requires a 1756-TBNH or 1756-TBSH removable terminal block (RTB) for installation in a grounded chassis. Part of the proven ControlLogix series, the 1756-OF6CI delivers reliable performance for demanding industrial environments.
Technical Specifications
Key specifications for the Allen-Bradley 1756-OF6CI module include:
- Output channels: 6 individually isolated current outputs
- Backplane current at 5V: 250 mA
- Backplane current at 24V: 300 mA
- Maximum power dissipation: 4.9 W at 60°C
- Isolation voltage: 50 V continuous
- Compatible RTBs: 1756-TBNH, 1756-TBSH
- Resolution: 13 bits (0 to 21.074 mA range)
- Module error: 0.6% of range
- Settling time: <2 ms to 95% of final value (resistive loads)
- Calibration accuracy: better than 0.1% of 4–21 mA at 25°C
Industry Applications
The 1756-OF6CI is ideal for upgrading legacy control systems or replacing older analog output modules in process industries. Typical applications include:
- Precise current loop control for valves, actuators, and transmitters in chemical plants
- High-accuracy signal conditioning in oil & gas refineries
- Isolated analog output for redundant safety systems in power generation
When replacing an older module, the 1756-OF6CI provides improved isolation and faster settling time, reducing downtime and enhancing system reliability.
Installation & Setup Guidance
Before installation, ensure the chassis is properly grounded and the RTB (1756-TBNH or 1756-TBSH) is attached. The module fits into any ControlLogix I/O slot. Wire each output according to the load requirements—the module supports 0–20 mA loops with load resistance up to 1000 ohms. For best performance, use twisted-pair shielded cables and separate power wiring from signal wiring. The module supports integer and floating-point data formats; configure the communication format in your controller program. No special tools are needed beyond standard wiring equipment.
Compatibility & Integration
The 1756-OF6CI integrates seamlessly with Allen-Bradley ControlLogix controllers (e.g., 1756-L6x, 1756-L7x) via the backplane. It supports data echo, ramping/rate limiting, clamping, and hold-for-initialization features. Use RSLogix 5000 or Studio 5000 for configuration. The module communicates using the ControlLogix backplane protocol—no additional network interfaces required. For mixed systems, verify that the chassis power supply can handle the total backplane current draw (250 mA at 5V + 300 mA at 24V).
Selection Guide & Purchasing Advice
When ordering the 1756-OF6CI, ensure you have the correct RTB (1756-TBNH or 1756-TBSH). Verify compatibility with your existing ControlLogix chassis and controller. The module is a Series A revision; it can be used as a direct replacement for older 1756-OF6CI modules or as an upgrade from non-isolated analog output modules. For bulk or OEM inquiries, contact UBEST Automation (visit ubest101.myshopify.com) for competitive pricing and lead times. Stock availability varies, so confirm before placing an order.