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
| Parameter Name | Parameter Value |
|---|---|
| Product Model | 1746-HSTP1/A |
| Manufacturer | Allen-Bradley (Rockwell Automation) |
| Product Type | Single-Axis Stepper Control Module |
| Compatible Platform | Allen-Bradley SLC 500 Series PLC |
| Axis Control | One (1) independent stepper axis |
| Output Signals | Pulse Train and Direction (differential line driver, RS-422 compatible) |
| Maximum Pulse Frequency | Up to 200,000 pulses per second (PPS) |
| Pulse Output Types | CW/CCW or Pulse/Direction (selectable) |
| I/O Connections | 40-pin ribbon cable to external drive interface module (1746-HS, 1746-HSCE) |
| Programmed Moves | Absolute, Incremental, Velocity, Homing, Jog |
| Motion Profile | Trapezoidal (programmable Accel, Decel, Slew Speed) |
| Inputs for Axis | 4 dedicated inputs (Home, Forward Limit, Reverse Limit, Drive Enable) + 4 general-purpose |
| Backplane Current Draw | 5V DC: 850 mA (typical) |
| Operating Temperature | 0 to 60 °C (32 to 140 °F) |
| Status Indicators | Module Status, Axis Status, and I/O status LEDs |
| Configuration | Configured via data table in SLC processor and RSLogix 500 software |
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.
