Allen-Bradley 1746-NO8V​ SLC 500 8-Channel Analog Voltage Output Module ±10V / 0–10V 16-Bit Resolution

Description

Technical Specifications

Main Features and Advantages

The Allen-Bradley 1746-NO8V​ distinguishes itself through software-driven flexibility, high-density packaging, and thoughtful field-service features that reduce downtime and simplify system commissioning.Software-configurable output ranges per channel: Unlike older analog modules that rely on physical DIP switches or range cards, the Allen-Bradley 1746-NO8V​ allows each of the eight channels to be independently assigned one of four voltage ranges (±10 V, 0–10 V, 0–5 V, 1–5 V) directly within the RSLogix 500 I/O configuration. This means a single module can simultaneously drive a ±10 V VFD speed reference on channel 0 and a 0–5 V positioner signal on channel 1—no hardware changes required when process requirements evolve.High-resolution 16-bit D/A conversion: The onboard digital-to-analog converter provides 65,536 discrete output steps, yielding smooth analog output with minimal quantization error. This is particularly beneficial in closed-loop analog control applications such as web tension, extruder barrel temperature profiling, or precision positioning where small setpoint increments matter.Removable terminal block with hot-swap capability: The supplied 1746-RT25G 18-position screw-terminal block latches onto the module front and can be unplugged with the module removed, allowing a faulty Allen-Bradley 1746-NO8V​ to be swapped without disturbing field wiring. This “wiggle-off” replacement preserves wiring integrity and shortens mean time to repair (MTTR) in operating plants.Flexible 24 V field-power sourcing: An onboard jumper (J4) lets the user choose whether the 24 V DC required for the output driver stage is drawn from the SLC 500 backplane (convenient in small panels) or from an externally supplied isolated 24 V DC source (preferred in electrically noisy environments or when segregating field power). This adaptability helps meet diverse panel-design and noise-immunity requirements.Comprehensive LED diagnostics: Eight green channel LEDs confirm that a non-zero output value is being driven, while the bi-color Module OK LED indicates communication with the processor (green steady) or fault conditions such as configuration mismatch, calibration error, or loss of backplane power (red flash/steady). This front-panel visibility accelerates troubleshooting without requiring a connected programming terminal.Optical isolation for system protection: 500 V DC isolation between field-side analog circuitry and the SLC 500 backplane guards the processor and other modules from ground loops, induced transients, and potential differences that commonly occur in industrial analog-field-wiring scenarios.

Application Field

The Allen-Bradley 1746-NO8V​ is deployed in SLC 500-controlled systems wherever multiple analog voltage setpoints must be distributed to field devices from a single chassis slot. In discrete manufacturing—such as automotive sub-assembly lines, stamping presses, and packaging machinery—it commonly supplies 0–10 V speed-reference signals to AC variable frequency drives on conveyors, winders, and stacker cranes, or ±10 V position commands to analog proportional hydraulic or pneumatic valves for press tonnage control, die cushion pressure, or web-guide actuator positioning.In process and batch applications—including water/wastewater treatment, chemical blending skids, food & beverage processing, and pharmaceutical pilot plants—the Allen-Bradley 1746-NO8V​ drives 4–20 mA-to-voltage-compatible recorders, strip-chart pens, and local analog displays, and provides 0–5 V or 1–5 V setpoints to electronic dosing-pump controllers or temperature loop manipulators. Its ability to mix output ranges on a per-channel basis makes it especially useful in hybrid machines where some devices require unipolar signals and others require bipolar command voltages.The module is equally at home in system-retrofit projects upgrading older fixed-I/O SLC 5/01 or 5/02 processors to modular SLC 500 racks with expanded analog capability. Because the Allen-Bradley 1746-NO8V​ requires no special chassis beyond a standard 1746 SLC 500 backplane and is fully addressed by slot position in the processor’s I/O image table, it drops seamlessly into existing SLC 500 architectures—making it a go-to choice for extending analog control capacity without migrating to a newer PLC platform.