1756-OF8I Allen Bradley Rockwell Analog Output Module

Product Parameters

Basic Information:

Manufacturer: Allen-Bradley (Rockwell Automation)

Model: 1756-OF8I (Series A)

Type: Analog Output Module with Individual Channel Isolation

Compatible Systems: ControlLogix series (compatible with PLC-5 via adapters)

Installation: Occupies one slot in a 1756 ControlLogix chassis, suitable for local or distributed I/O configurations

Module Location: Can be installed in any slot of the ControlLogix chassis

Electrical Parameters:

Output Channels: 8 individually isolated analog outputs

Output Signal Ranges:

Voltage: ±10V, 0–10V, 0–5V

Current: 0–20 mA (commonly 4–20 mA)

Resolution:

Voltage: 16 bits across 20.78V (320 µV/bit)

Current: 16 bits across 21 mA (320 nA/bit)

Backplane Current:

250 mA @ 5.1V DC

225 mA @ 24V DC

Backplane Power: 6.7 W (maximum)

Power Dissipation: 

Voltage: 3.7 W

Current: 5.1 W (at 700 Ω load)

Thermal Dissipation: 

Voltage: 12.62 BTU/hour

Current: 17.39 BTU/hour

Output Impedance:

Voltage: <1 Ω

Current: >1 MΩ

Drive Capability:

Voltage: >1000 Ω (minimum load)

Current: 0–1000 Ω

Calibration Accuracy: 0.05% (voltage and current)

Module Error:

Voltage: 0.1%

Current: 0.1%

Offset Drift:

Voltage: 100 µV/°C

Current: 200 nA/°C

Gain Drift:

Voltage: 25 ppm/°C

Current: 50 ppm/°C

Overvoltage Protection: ±30V DC (current mode)

Short-Circuit Protection: Electronically limited to 21 mA or less (current mode)

Isolation Voltage:

250V continuous (channel-to-channel and channel-to-backplane)

Tested at 1500V AC for 60 seconds (basic insulation)

Tested at 2300V AC for 60 seconds (reinforced insulation, outputs to backplane)

Settling Time: <1 ms to 95% of final value

Module Scan Time:

Integer format: 8 ms

Floating point format: 12 ms

Connection and Wiring:

Removable Terminal Blocks (RTBs):

1756-TBCH: 36-position Cage-Clamp block

1756-TBS6H: 36-pin spring clamp block

Wire Size:

0.33–2.1 mm² (22–14 AWG) solid or stranded shielded copper wire, rated at 105°C (221°F) or greater, 1.2 mm insulation max

Torque: 0.5–0.6 Nm (4.4–5.3 lb-in) for 1756-TBCH

Environmental Specifications:

Operating Temperature: 0°C to 60°C (32°F to 140°F)

Storage Temperature: -40°C to 85°C (-40°F to 185°F)

Relative Humidity: 5% to 95% (non-condensing)

Vibration: 2G @ 10–500 Hz

Shock: 30G (operating)

Enclosure Type: Open-type

Temperature Codes: T4 (North America, IEC, ATEX)

Other:

Conversion Method: R-Ladder DAC, monotonicity with no missing codes

Data Formats: IEEE 32-bit floating point, Integer (left-justified, 2’s complement)

Certifications: UL, CSA, CE, C-TICK, ATEX, FM, KC, IECEx, ABS

Functions

Analog Output Control:

Provides 8 individually isolated analog output channels configurable for ±10V, 0–10V, 0–5V, or 0–20 mA (commonly 4–20 mA), enabling precise control of analog devices like valves, actuators, or variable frequency drives (VFDs).

Channel-to-Channel Isolation:

Each of the 8 channels is individually isolated, preventing interference between channels and ensuring reliable operation in applications with multiple independent signal paths.

High-Resolution Output:

Offers 16-bit resolution for voltage (320 µV/bit) and current (320 nA/bit), providing higher accuracy compared to the 15-bit resolution of the 1756-OF8 and 1756-OF8H.

Protection Features:

Overvoltage Protection: Protects against ±30V DC in current mode.

Short-Circuit Protection: Electronically limits current to 21 mA or less to prevent damage.

Open-Circuit Detection: Detects open circuits in current mode, enhancing system reliability.

Diagnostics and Alarming:

Supports real-time channel sampling and onboard data alarming for immediate fault detection (e.g., over/under range, open circuit).

Provides detailed diagnostic information via Studio 5000 Logix Designer, improving maintenance efficiency.

Flexible Data Handling:

Supports IEEE 32-bit floating point and Integer data formats for compatibility with various control algorithms.

Uses R-Ladder DAC for accurate and monotonic signal conversion.

System Integration:

Integrates seamlessly with ControlLogix controllers via ControlNet, EtherNet/IP, or DeviceNet networks.

Supports local or distributed I/O configurations, compatible with Studio 5000 Logix Designer for configuration and diagnostics.

Modular Design:

Supports Removal and Insertion Under Power (RIUP) with removable terminal blocks (1756-TBCH, 1756-TBS6H), simplifying maintenance and reducing downtime.

Application Scenarios

Industrial Process Control:

Controls analog devices like valves, pumps, or actuators in industries such as chemical processing, oil and gas, or water treatment, where channel isolation is critical to prevent signal interference.

Ideal for precise modulation of flow, pressure, or temperature in complex processes.

Manufacturing Automation:

Drives VFDs or servo motors in production lines for automotive manufacturing, packaging, or material handling.

Ensures accurate speed or position control in conveyor systems or robotic arms, with isolated channels reducing crosstalk risks.

Distributed Control Systems:

Used in distributed I/O setups via ControlNet or EtherNet/IP, enabling centralized control of remote analog devices in large-scale facilities like power plants or refineries.

Critical Applications Requiring Isolation:

Suitable for applications where independent signal paths are essential, such as multi-loop control systems or environments with high electrical noise (e.g., heavy industrial settings).

Legacy System Upgrades:

Integrates with PLC-5 systems (via adapters) or serves as a key component in modernizing to ControlLogix platforms, maintaining compatibility with legacy infrastructure while offering enhanced isolation and resolution.

Harsh Environment Applications:

Robust design with vibration (2G) and shock (30G) resistance makes it suitable for demanding environments like mining, marine, or heavy machinery control.

Advantage Products:

All items are Distributor Ready-stock Genuine Brand-new Supplying, please inform us if the other conditions are needed, Used, Open-box, Refurbished, etc.

Many Available just wait for you, feel free to ask to get better deal!!!

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