Stockroll Profile Tester

Project Description

As part of a total quality control system in a magnetic tape manufacturing plant, the customer required a piece of test equipment to measure the profile of the edge of a roll of magnetic tape and qualify the profile as a pass/fail test.

The profiling is accomplished using a laser displacement gauge mounted on an X-Y table driven by stepper motors. This system is controlled by a PC connected to a LAN. A hand-held laser bar-code scanner is the sole input device, used to read stockroll numbers and to input control commands. A log file is maintained which details the product tested, the number of retests, the operator and shift, date and time in addition to the pass/fail indication. Calibration functions are include to provide traceability and allow easy verification of proper operation. An owner’s manual was prepared to document all aspects of program operation and provide for continuation support.

Skills Required

While this was mainly a software project, Embedded Systems performed several ancillary functions which led to the eventual success of this project. This included assistance evaluating and tuning different models of the laser displacement gauge. The software was written In Microsoft “C” using LabWindows as a graphical user interface. The X-Y table was controlled by an intelligent interface card with a file-type interface. In addition to coding the functional portions of the application, a considerably amount of effort was dedicated to optimizing the speed of the testing operation by running the X-V table as fast as possible without positioning errors. Also, additional effort was expended to verify repeatability and accuracy of the device.

Services Used

  • Design and coding of “C” applications
  • Use of LabWindows interface
  • Technical writing
  • On-site installation and support
  • Project Size
  • 4 man-months of effort


A Magnetic Media Manufacturer