Category: Industry trends

Product Overview

The Allen-Bradley 1746-OV8/A​ is a fundamental 8-channel discrete DC output module from the prolific SLC 500 modular I/O system. This module functions as a critical interface between the programmable logic controller’s (PLC) logic solver and real-world DC actuation devices. Its primary role is to convert low-voltage digital command signals from the SLC 500 processor into robust, switched 24V DC power outputs capable of directly driving industrial loads. Each of the eight output channels acts as an independent electronic switch (sinking type) that closes to complete the circuit to ground, allowing current to flow from an external 24V DC supply through the connected load and into the module. The Allen-Bradley 1746-OV8/A​ is engineered for reliability and simplicity, providing a standardized method to command a variety of field devices such as relay coils, solenoid valves, pilot lights, and small motor starters based on the control program’s logic.As a core component within the SLC 500 platform, the 1746-OV8/A​ is designed for easy integration into a 1746 series I/O chassis, where it occupies a single slot. It represents the “muscle” of the control system, executing the commands determined by the processor’s ladder logic. The module provides electrical isolation between the sensitive internal logic circuits of the PLC and the potentially noisy power circuits of the field devices, enhancing system stability and protection. The value of the Allen-Bradley 1746-OV8/A​ lies in its proven durability, straightforward application, and pivotal role in closing the control loop. It translates complex automation algorithms into actionable physical outputs, enabling machinery to start, stop, position, and sequence operations. Its 8-point configuration offers a cost-effective density for a wide range of machine and process control applications, making it one of the most commonly deployed output modules in the extensive SLC 500 I/O catalog.

Technical Specifications

Main Features and Advantages

The Allen-Bradley 1746-OV8/A​ is distinguished by its robust and reliable solid-state design. Utilizing transistor outputs provides significant advantages over mechanical relay outputs, including faster switching speeds (suitable for pulse outputs up to 1 kHz), silent operation, and a much longer operational life with no moving parts to wear out. The sinking output configuration is a common industry standard, offering compatibility with a vast array of 24V DC industrial devices. Each output is protected by internal electronic fusing, which helps prevent damage to the module from short-circuit or overload conditions on any individual channel, enhancing overall system robustness and reducing maintenance costs. The module’s outputs are arranged in groups (typically two groups of four) with separate common terminals, providing flexible wiring options and allowing different sections of a machine to be powered from separate DC supplies if needed.Ease of use and integration are hallmarks of the Allen-Bradley 1746-OV8/A. Its clear per-point LED indicators provide instant visual confirmation of the output status, which is invaluable for troubleshooting and commissioning. The module interfaces with the SLC 500 processor via the chassis backplane, requiring no complex configuration—it is automatically recognized as an output module. Installation is simplified by the use of removable terminal blocks, which allow wiring to be completed on a bench before the module is snapped into the chassis. The Allen-Bradley 1746-OV8/A​ is designed for the demanding environment of industrial control panels, with a wide operating temperature range and protection against electrical noise. Its proven track record of reliability in countless installations makes it a trusted choice for system integrators and maintenance personnel, ensuring dependable performance for driving the essential actuators that make automated processes function.

Product Overview

The Allen-Bradley 1746-OBP16 is a 16-channel, DC sourcing output module designed for the SLC 500 programmable controller system from Rockwell Automation. This module serves as a critical interface between the digital logic of the SLC 500 processor and the physical actuators in an industrial environment. Its primary function is to convert low-power logic signals from the controller’s backplane into isolated switching signals capable of controlling external DC loads. The Allen-Bradley 1746-OBP16​ operates on the “sourcing” principle, meaning that when a channel is activated (turned ON by the PLC logic), it internally connects the load to the common positive voltage source (+VDC), allowing current to flow from the module’s terminal, through the load, to ground. This positive logic, 12-24 VDC module is engineered to reliably drive a wide array of field devices, providing the essential link that transforms control program decisions into physical actions on the factory floor.As a member of the extensive 1746 I/O module family, the 1746-OBP16​ is a fundamental building block for expanding the output capacity of any SLC 500 system, whether housed in a 4-slot, 7-slot, 10-slot, or 13-slot chassis. Its “OBP” designation breaks down as: “O” for Output, “B” for the specific electrical design series, and “P” for Positive Logic (sourcing). The module is valued for its high density (16 points in a single slot), straightforward integration, and proven reliability. In a typical control panel, the Allen-Bradley 1746-OBP16​ would be used to energize indicator lamps, small relays, solenoid valves, and other DC-powered devices that require a robust and electrically isolated switching signal. By providing individually fused outputs and optical isolation, the module protects the sensitive SLC 500 backplane from potential field-side faults like short circuits or overcurrent conditions. The 1746-OBP16​ represents a classic, workhorse output solution that has been instrumental in countless automation applications, known for its durability and ease of use in demanding industrial settings.

Technical Specifications

Main Features and Advantages

The Allen-Bradley 1746-OBP16​ output module delivers a robust set of features centered on protection, diagnostics, and ease of use. A primary advantage is its individual electronic fuse protection for each of the 16 output channels. This sophisticated design isolates a fault to the specific channel where it occurs—such as a shorted solenoid coil—preventing the fault from affecting neighboring channels or causing the module’s entire power supply to shut down. When a fuse operates, the channel’s LED indicator will flash, providing immediate visual diagnostics that guide the technician directly to the problematic circuit, dramatically reducing mean-time-to-repair (MTTR).Reliable Sourcing Design and Clear Diagnostics: The module’s sourcing (positive logic) output design is intuitive for many control panel layouts, where a common positive 24VDC rail is distributed. The 1746-OBP16​ provides excellent electrical isolation (500V rms) between the field wiring and the controller’s sensitive backplane, protecting the PLC from voltage transients and noise. Each channel’s bright red LED gives unambiguous confirmation of the output’s commanded state from the PLC program. The module is designed for high inrush capability, allowing it to reliably energize loads like solenoid valves and small relay coils that have high initial turn-on currents. Furthermore, the Allen-Bradley 1746-OBP16​ is engineered for the rigors of the industrial environment, with a wide operating temperature range and robust construction. Its use of a removable terminal block simplifies wiring and maintenance, as the entire block can be pre-wired on a bench before being snapped onto the module. This combination of high-density point count, individual channel protection, and clear diagnostics makes the 1746-OBP16​ a dependable and cost-effective choice for a vast array of standard DC output applications in SLC 500 systems.

Product Overview

The Allen-Bradley 1746-NO8V/A​ is an 8-channel, voltage-output analog output module designed for the Allen-Bradley SLC 500 programmable controller system. This module serves as a critical interface that translates digital control signals from the SLC processor into precise analog voltage signals used to command and regulate field devices. It occupies a single slot in a 1746 I/O chassis and provides eight independent output channels, each capable of generating a configurable voltage signal, typically in the industry-standard 0 to 10V DC range. The Allen-Bradley 1746-NO8V/A​ is engineered to control a wide array of analog actuators, including variable frequency drive (VFD) speed references, proportional valve positioners, analog chart recorders, and process controllers. Its function is to close the control loop by delivering the precise analog command signal calculated by the PLC’s logic or PID algorithm, enabling continuous modulation of speed, position, flow, or other process variables.As a key component in the SLC 500 I/O family, the 1746-NO8V/A​ provides a high-density, cost-effective solution for applications requiring multiple analog control outputs. Each channel is independently configurable via the controller’s programming software (such as RSLogix 500), allowing for different output ranges and data formats to match the requirements of the connected device. The module receives digital data words from the SLC processor over the chassis backplane, performs digital-to-analog conversion (DAC) with high resolution, and outputs a stable, low-noise voltage signal. The “/A” suffix often denotes a specific hardware revision or a standard product version. The design of the Allen-Bradley 1746-NO8V/A​ emphasizes accuracy and stability, incorporating features to minimize the impact of electrical noise commonly found in industrial environments. By providing reliable analog command signals, this module enables the SLC 500 platform to perform sophisticated closed-loop control tasks in process industries, machine control, and building automation, extending the utility of this versatile controller beyond simple discrete logic.

Technical Specifications

Product Overview

The Allen-Bradley 1746-ITV16​ is a 16-point, 24V DC digital input module designed for the Allen-Bradley SLC 500 modular programmable controller system. This specific module, with the common hardware revision 1746-ITV16-A, is engineered to interface field devices that provide a “sourcing” DC signal to the PLC. In electrical terms, a sourcing field device (like a PNP proximity sensor) provides a positive voltage (+24V DC) when active. The Allen-Bradley 1746-ITV16​ is configured as a “sinking” input module; it provides a common connection to the DC negative (Common) and “sinks” the current from each active input point to complete the circuit. This module is a critical interface that converts the state of real-world devices—such as pushbuttons, limit switches, proximity sensors, and photoelectric eyes—into a digital logic level (1 or 0) that the SLC 500 processor can read and evaluate within its control program.Occupying a single slot in an SLC 500 chassis (like the 1746-BAS), the 1746-ITV16-A​ provides a high-density, 16-point solution for gathering discrete status information. Its value lies in its robust industrial design, offering reliable signal conditioning and electrical isolation to protect the sensitive backplane and CPU from voltage transients, noise, and wiring errors present in the plant environment. Each input channel is individually isolated and includes filtering to debounce mechanical switch contacts and reject electrical noise, ensuring clean and accurate data for the control logic. The module’s design simplifies wiring with a removable terminal block that accommodates standard wire gauges, and its front panel features LEDs that indicate the status (ON/OFF) of each input point, enabling quick visual diagnostics during operation or troubleshooting. The Allen-Bradley 1746-ITV16​ is a fundamental building block for creating reliable machine control systems, enabling the PLC to safely and accurately monitor the state of a wide array of industrial sensing devices.

Technical Specifications

Product Overview

The ALLEN-BRADLEY 1746-IH16A is a high-voltage digital input module designed for the Allen-Bradley SLC 500 series of modular programmable controllers. This module provides a robust 16-channel interface, specifically configured for sinking input​ operation, capable of accepting a wide range of input voltages. A key distinguishing feature of the ALLEN-BRADLEY 1746-IH16A​ is its ability to accept both AC and DC input signals, with a nominal operating voltage of 120V. This dual compatibility makes it exceptionally versatile for directly interfacing with a broad array of industrial field devices without requiring intermediate interfacing components. Its primary function is to convert the on/off state of high-voltage field devices, such as limit switches, selector switches, pushbuttons, and proximity sensors, into a logic-level signal that the SLC 500 processor can read and process within its control program.Installed into an I/O slot of a compatible 1746 series chassis, such as the 1746-A13B, the ALLEN-BRADLEY 1746-IH16A​ forms a critical link between the high-power control circuit and the low-voltage logic of the PLC. Each of its 16 input points is designed to accept a sinking (NPN) signal; meaning the field device provides a path to common (sinks current) when active. The module itself sources a small sensing current. The wide voltage acceptance range (79-132V AC/DC) ensures reliable operation despite typical line voltage fluctuations. The ALLEN-BRADLEY 1746-IH16A​ is engineered for industrial durability, incorporating features like optical isolation between each input channel and the internal logic circuits. This isolation is critical for protecting the sensitive processor and other modules from voltage transients, noise, and potential ground loops present in the high-voltage field wiring. The deployment of the ALLEN-BRADLEY 1746-IH16A​ is a strategic choice for applications where devices operate directly on 120V control power, simplifying wiring diagrams by eliminating the need for separate 24V DC power supplies for sensors and allowing for direct monitoring of devices like motor contactor auxiliary contacts. It represents a reliable, high-density solution for consolidating high-voltage discrete signals into a centralized SLC 500 control system.

Technical Specifications

Product Overview

The Allen-Bradley 1746-IG16​ is a high-density, 16-channel digital input module designed for the Allen-Bradley SLC 500 modular programmable logic controller (PLC) system. This module serves as a critical interface between the PLC’s central processor and the field devices, providing a reliable means to read the on/off status of sensors, switches, pushbuttons, and other discrete devices. Specifically configured for 24VDC sinking (NPN) input circuits, the Allen-Bradley 1746-IG16​ is engineered to convert the presence or absence of a 24VDC signal at its terminals into a logical 1 or 0 that the SLC 500 processor can utilize in its control program. Each of its 16 channels is individually isolated in groups and features diagnostics like LED status indicators, making it a fundamental component for machine control, process monitoring, and safety interlocking in a wide range of industrial automation applications.Installed into any available I/O slot of an SLC 500 chassis (such as the 1746-A7), the 1746-IG16​ module communicates with the processor via the chassis’s high-speed parallel backplane. Its design emphasizes ease of use and reliable signal acquisition in noisy industrial environments. The module’s input circuits require a 24VDC sourcing (positive) common, meaning the field device (sensor/switch) acts as the sink to ground when activated. This is a common configuration for many industrial proximity sensors and photoelectric switches. The Allen-Bradley 1746-IG16​ provides internal optical isolation between the field wiring and the controller’s logic, protecting the sensitive processor from voltage transients and ground loops that can occur in plant environments. With its balanced 16-point density, it offers an efficient use of chassis space, allowing a significant number of digital sensors to be monitored from a single module slot. As a core part of the extensive SLC 500 I/O family, the 1746-IG16​ represents a proven, cost-effective solution for gathering discrete status information in centralized control systems, contributing to the platform’s reputation for durability and straightforward integration.

Technical Specifications

Product Overview

The Allen-Bradley 1746-IB16/C​ is a fundamental and widely used 16-channel, 24V DC digital input module designed for the Allen-Bradley SLC 500 modular programmable controller system. This module serves as a primary interface for connecting a variety of DC field devices—such as pushbuttons, limit switches, photoelectric sensors, and proximity switches—to the SLC 500 processor. Its core function is to read the on/off status of these devices by sensing the presence or absence of a 24V DC signal at each of its 16 input points, converting these physical states into digital data that the SLC processor can use in its control logic. The Allen-Bradley 1746-IB16/C​ is characterized as a “sinking” input module, meaning that to signal an ON (or logic 1) state, the field device must source current intothe module’s input terminal, a wiring configuration that is standard for many industrial sensors and switches.As part of the enduring 1746 I/O family, this module slots into a 4-, 7-, 10-, or 13-slot 1746 chassis, communicating with the processor over the proprietary backplane. Its design emphasizes reliability, simplicity, and cost-effectiveness for high-density discrete input applications. Each channel is electrically isolated in groups (typically in banks of 8) and includes status LEDs for visual indication of the input state, which is invaluable for troubleshooting. The Allen-Bradley 1746-IB16/C​ represents the workhorse of discrete automation for thousands of factories worldwide. It is a cornerstone component in the vast installed base of SLC 500 systems, which, despite being a legacy platform, continues to operate reliably in countless facilities. For maintenance technicians, system integrators, and plant engineers, the 1746-IB16/C​ is a critical spare part. Its failure can incapacitate multiple machine inputs, and its availability is essential for supporting the ongoing operation, repair, and minor expansions of these reliable and cost-effective control systems, ensuring continued productivity without the need for a full system overhaul.

Technical Specifications

Product Overview

The Allen-Bradley 1746-IB8​ is a classic, 8-channel, 24V DC sinking digital input module, a fundamental building block for the widely deployed Allen-Bradley SLC 500 programmable logic controller (PLC) system. This module serves as a primary interface between the physical world of field devices and the logical world of the PLC’s processor. It is designed to reliably read the on/off status of industrial sensors and switches—such as push buttons, limit switches, proximity sensors, and photoelectric eyes—converting their 24V DC signals into a logic-level format that the SLC 500 processor can interpret within its control program. The 1746-IB8​ is categorized as a “sinking” input module, meaning that to activate an input, the connected field device must source 24V DC current intothe module’s input point, a common and robust wiring configuration in industrial control panels. This module represents a workhorse component of countless automation systems installed over several decades, providing dependable, noise-immune signal acquisition for discrete control applications.As part of the 1746 modular I/O family, the Allen-Bradley 1746-IB8​ is designed to be installed in a 1746 I/O chassis, which houses the SLC 500 processor, power supply, and other I/O modules. Its value lies in its simplicity, proven reliability, and ease of integration. Each of the eight optically isolated input channels provides a clear status indication via an LED, allowing for quick visual diagnostics. The module plays a critical role in machine and process control by feeding real-time data about the state of the manufacturing floor—whether a part is present, a door is closed, or a cycle is complete—to the central controller. For facilities operating and maintaining SLC 500-based systems, the 1746-IB8​ remains an essential spare part for repairs, system expansions, and legacy machine support, ensuring the continued operation of vital industrial infrastructure.

Technical Specifications

Product Overview

The Allen-Bradley 1746-HSTP1/A​ is a high-speed, single-axis stepper control module designed for the Allen-Bradley SLC 500 programmable logic controller (PLC) platform. This specialized I/O module integrates motion control functionality directly into the PLC rack, allowing an SLC 5/03, 5/04, or 5/05 processor to command and control a stepper motor drive for precise positioning applications. The Allen-Bradley 1746-HSTP1/A​ generates the necessary pulse and direction signals required by a standard stepper motor drive or translator, effectively serving as the intelligent motion command generator while the external drive handles the power stage and current control for the motor. This architecture provides a cost-effective and integrated solution for adding a single axis of coordinated motion to a machine primarily controlled by an SLC 500 PLC, eliminating the need for a separate motion controller in many applications.As a member of the 1746 I/O family, the 1746-HSTP1/A​ module occupies a single slot in the SLC 500 chassis and communicates with the processor over the proprietary backplane, ensuring fast and deterministic data exchange. It is capable of managing complex motion profiles, including trapezoidal velocity profiling with programmable acceleration, deceleration, slew speed, and target position. The module can execute moves in absolute or incremental modes and supports functions like homing (search for limit or home switch) and jogging. The value of the Allen-Bradley 1746-HSTP1/A​ lies in its ability to bring basic yet powerful single-axis positioning under the direct program control of the SLC processor. This enables seamless synchronization between the motion axis and other machine sequences controlled by the PLC, such as clamping, pressing, or inspection stations. It simplifies programming and troubleshooting by consolidating logic and motion control within a single hardware platform and software environment (RSLogix 500), making it an ideal choice for applications like indexing tables, linear actuators, pick-and-place units, and simple gantry systems where a dedicated multi-axis controller would be overkill.

Technical Specifications

Main Features and Advantages

Integrated PLC-Based Motion Control: The primary advantage of the Allen-Bradley 1746-HSTP1/A​ is its deep integration with the SLC 500 platform. It communicates with the processor over the high-speed backplane, allowing the motion commands and status to be handled as regular I/O data within the PLC’s ladder logic program. This eliminates the complexity of setting up communication between a separate motion controller and a PLC. Programmers can use familiar ladder logic instructions to command moves, monitor axis status, and handle faults, creating a unified control program. The module uses a dedicated block of the SLC’s data table for configuration and control, making programming straightforward within the RSLogix 500 environment.

Product Overview

The Allen-Bradley 1746-FIO4V/A​ is a versatile and space-saving 4-channel analog combination input/output (I/O) module designed for the Allen-Bradley SLC 500 modular controller platform. This module provides a hybrid solution by integrating both analog input and analog output functionality into a single, compact slot within an SLC 500 chassis. The Allen-Bradley 1746-FIO4V/A​ is specifically configured to handle voltage signals, typically offering two channels of analog input and two channels of analog output, making it an ideal choice for applications requiring a mix of monitoring and control without consuming multiple slots in the controller rack. Its core value lies in its ability to create a complete, compact control loop interface—for example, reading a process variable (like pressure or temperature via a transmitter) and sending a corrective control signal (to a valve actuator or variable speed drive)—all from one integrated module, thereby optimizing rack space and reducing system cost.As a member of the extensive 1746 I/O family, the 1746-FIO4V/A combination module​ communicates directly with the SLC 5/03, 5/04, or 5/05 processor over the proprietary backplane, ensuring fast and deterministic data exchange. The “V” in its model number denotes its primary voltage signal compatibility (e.g., 0-10V DC, ±10V DC), and the “/A” suffix indicates a specific product revision. This module serves as a critical interface for applications that require both sensing and actuation in the analog domain, bridging the gap between the digital world of the PLC and the continuous variable signals of the process world. By providing a balanced mix of inputs and outputs, the Allen-Bradley 1746-FIO4V/A​ offers system designers exceptional flexibility for small to mid-sized control systems, process skids, and machine automation where a full slot dedicated solely to inputs or outputs would be inefficient.

Technical Specifications

Main Features and Advantages

Space-Efficient, Integrated Design: The most prominent advantage of the Allen-Bradley 1746-FIO4V/A​ is its combination of input and output functionality in a single module slot. In the SLC 500 system, where rack space is a finite and valuable resource, this design allows engineers to implement both sensing and control for a process using only one slot instead of two. This optimization is crucial for compact control panels, packaged skids, or when expanding an existing system with limited free slots remaining. The 1746-FIO4V/A combination module​ provides a cost-effective and physically compact solution for implementing complete analog control loops, such as a single PID loop controlling a tank level or temperature.High Resolution and Flexible Configuration: The module delivers high-performance analog conversion with 16-bit resolution for both input and output channels, ensuring precise measurement and control. Each of the two input and two output channels can be independently configured via the SLC 500 programming software (RSLogix 500) for different voltage ranges. This flexibility allows the same Allen-Bradley 1746-FIO4V/A​ module to interface with a variety of field devices—for example, one input could be set for a 4-20mA signal (with a precision resistor) reading pressure, while the output could be set for a 0-10V signal controlling a drive. The module includes diagnostic LEDs that provide immediate visual feedback on module status and communication health, aiding in quick troubleshooting. Its robust design with internal isolation helps maintain signal integrity in electrically noisy industrial environments.