1756-OF4 Allen-Bradley ControlLogix Analog Output Module

Overview:

The Allen-Bradley 1756-OF4 is a four-channel analog output module designed for use with the ControlLogix series by Rockwell Automation. It offers the flexibility of both voltage and current signals, providing an output voltage range of ±10V and a current range of 4-20 mA. This module is perfect for driving modulating actuators, such as control valves, dampers, or frequency drives, and can be integrated into advanced control strategies like PID control and cascade control. Whether you’re controlling equipment directly or transmitting data to external controllers, the 1756-OF4 meets the needs of various industrial applications.

Technical Specifications:

• Brand: Allen-Bradley (Rockwell Automation)
• Model: 1756-OF4
• Part Number/Catalog No.: 1756-OF4
• Module Type: Analog Output Module (Four Channels)
• Output Voltage Range: ±10V
• Output Current Range: 4–20 mA
• Output Voltage Resolution: 15 bits (320 µV/bit across 10.5V)
• Output Current Resolution: 15 bits (650 nA/bit across 21 mA)
• Power Supply (Backplane): 150 mA at 5V DC, 120 mA at 24V DC
• Power Dissipation: Max 4.9W at 60°C
• Isolation Voltage: 50V continuous
• Removable Terminal Block (RTB) Compatibility: 1756-TBSH, 1756-TBNH
• Maximum Power Dissipation: 3.25W (for 4-channel current)
• Module Scan Time: 12 ms (floating-point), 8 ms (integer mode)
• Overvoltage Protection: 24V DC
• Settling Time: < 2 ms to 95% of final value (resistive loads)
• Thermal Dissipation: 10.91 BTU/hr
• Maximum Output Drive Capability:
  • Voltage: > 2000 ohms
  • Current: 0–750 ohms

Ordering Information:

• Part Number: 1756-OF4
• Related Terminal Blocks:
  • 1756-TBSH (for shielded wire)
  • 1756-TBNH (for non-shielded wire)

Ensure to verify the compatibility with the ControlLogix chassis for proper installation.

FAQ:

1. What is the voltage and current range of the 1756-OF4 module?
   • The 1756-OF4 provides ±10V for voltage output and 4-20 mA for current output.
2. What is the resolution of the output signals?
   • The voltage output has a resolution of 15 bits across 10.5V, with 320 µV/bit, and the current output has a resolution of 15 bits across 21 mA, with 650 nA/bit.
3. Can the 1756-OF4 be used for PID control?
   • Yes, the module is suitable for controlling actuators in PID control loops, as well as other advanced control strategies.

Check official datasheet for more detailed information: ControlLogix and GuardLogix Controllers