B&R 7AO352.70 System 2003 Analog Output Module

Product Overview

The 7AO352.70 (7AO352.70) is a high-precision analog output module designed for the legacy B&R System 2003 platform. Engineered for critical process control applications—such as variable speed drive regulation, proportional valve positioning, and industrial heating control—this module provides two high-resolution outputs. Supporting both voltage (±10 V) and current (0 to 20 mA) signals with 12-bit resolution, the 7AO352.70 ensures smooth and accurate transitions in automation workflows. Its rugged screw-in form factor and extensive certifications for hazardous locations make it a reliable choice for retrofitting or maintaining complex industrial systems in chemical processing, oil and gas, and power generation sectors.

Signal Control and Precision Engineering

The 7AO352.70 is optimized for versatility, allowing engineers to interface with a wide variety of field actuators and controllers without the need for additional signal converters.

• Dual-Mode Outputs: Each of the two channels can be independently configured to output standard ±10 V voltage signals or 0 to 20 mA current loops, providing flexibility for diverse global equipment standards.

• 12-Bit Resolution: With a resolution of 12-bit, the module divides the output range into 4,096 distinct steps, ensuring fine-tuned control over mechanical movements and process variables.

• Screw-in Architecture: The module is designed as a secure screw-in unit for the System 2003 rack, ensuring maximum mechanical stability even in high-vibration environments.

Technical Specifications

Technical FAQs

How do I switch between the ±10 V and 0 to 20 mA output modes?

The output mode for the 7AO352.70 is typically determined by the wiring configuration on the terminal block and the hardware parameter settings within the B&R programming environment. Consult your specific system documentation to ensure the software configuration matches the physical wiring to prevent component damage.

Is the terminal block included with the module?

No, the 7AO352.70 is supplied as the core screw-in module only. To complete the installation and field wiring, you must order the TB712 terminal block as a separate line item.

What does the cULus HazLoc certification mean for my installation?

This certification indicates that the 7AO352.70 is safe for use in Class I, Division 2 environments. This means it is engineered to operate safely in locations where flammable gases or vapors may be present under abnormal conditions (Groups ABCD), providing an extra layer of safety for refinery or chemical plant applications.

Field Engineering & Installation Guide

• Terminal Block Integration: Ensure the TB712 terminal block is seated firmly before tightening the module's mounting screws. Use a torque-limited screwdriver to avoid over-tightening, which can stress the internal PCB connectors over time.

• Signal Shielding: For analog signals, especially ±10 V voltage outputs, use twisted-pair shielded cabling. Ground the shield at only one end (preferably at the control cabinet's common ground rail) to eliminate ground loops that can introduce jitter into the 12-bit signal.

• Load Impedance Awareness: When operating in current mode (0 to 20 mA), verify that the total loop resistance does not exceed the module's maximum drive capacity. Excessive resistance will cause the output to "flatline" before reaching the maximum 20 mA value.

Engineering Advantages

The 7AO352.70 stands out for its robust environmental resilience. While many modern modules prioritize plastic housings, this System 2003 unit is built for longevity in harsh "legacy" environments. Its ability to operate in Class I, Div 2 hazardous locations without additional purging equipment saves significant installation costs. Furthermore, the 12-bit resolution provides a "sweet spot" for industrial actuators, offering a balance of high-speed response and sufficient granularity for most industrial PID control loops.