A-B 1746-IA4 Module Rockwell SLC 4 Digital Inputs

 Module Overview

 Chapter Objectives

 Stepper Controller

The Module supports two differential outputs, to suit the type of Stepper Translator used, which provide the following control commands:

 • CW or non-directional pulse output

 • CCW or direction signal output

 Discrete inputs are provided for:

 • External Interrupt

 • Home Limit Switch

 • Home Proximity Input

 • CW Travel Limit Switch Input

 • CCW Travel Limit Switch Input

 • Pulse Train Enable/Disable Input

Differential inputs are provided for:

 • Encoder Channel A and A NOT

 • Encoder Channel B and B NOT

 • Encoder Marker Channel

The Module overview will permit you to understand the basic functions of the Module and hardware requirements.

 The Module, catalog number 1746–HSTP1, is an SLC 500 family compatible device. It can be used with any SLC 500 Processor.

 The Module is configured through the SLC 500 backplane and requires no switch settings. 

Motion can be programmed in either direction for over ±8,000,000 counts of absolute position.

An optional incremental encoder may be used to verify the position reached by the axis. 

The Module does not automatically close a position loop in engineering units. 

The feedback hardware can accept frequencies of up to 250 kHz for use as either loop back diagnostics or differential incremental encoder feedback devices.

The Module can be programmed for either incremental or absolute moves, depending on the application.

Command Mode Operation All stepper motor operations are performed in command mode. 

This mode is entered by setting the mode flag (bit 15 in output word 0) to 0.

In command mode, the SLC Processor can issue commands and activate different operations or moves. The actions you can command are:

 • Absolute Moves

 • Relative Moves

 • Hold Moves

 • Resume Moves

 • Immediate Stop Operations

 • Homing Operations

 • Jogging Operations

 • Blend Moves

 • Preset Operations

 • Reset Errors

Diagnostic Mode

Use the configuration mode to select the diagnostic mode of operation. Once selected, 

the diagnostic mode allows you to test your program and wiring by connecting the loop back wires at the 

translator. The purpose of loop back diagnostics is to test the system wiring for electrical noise. 

The number of pulses received at the feedback should equal the commanded number of pulses at the end of the move. 

If they are not equal, the system may be experiencing problems due to electrical noise.