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 Software Tools for Measurement Inspection

Architecture - DOT Equipment Plug-ins
 
Equipment Plug-in Architecture Diagram
 
 
DOT Logo The DOT Equipment Plug-in contains all of the DME-specific code within the DOT system architecture. This plug-in provides a mapping between the DMIS Part 2 API calls and the inspection device controller(s). The DOT plug-in routes the API calls - such as probing, motion, and sensor selection - to the appropriate hardware to initiate controller-specific inspection operations.

The DOT Equipment Plug-in has a number of classes that simplify the task of supporting a variety of different controllers; and its modular design provides a structured framework that minimizes the amount of code needed to support many machine controllers.

 
  bullet3.gif Control and State Logic
Commands and data requests from the DMIS Part 2 interfaces are handled by this logic, which routes the request data to methods on the internal objects. This code also manages state information about sensor selection, probe compensation, and operating status; and provides general synchronization for multi-carriage (multi-threaded) operation.

bullet3.gif Modular Controller Interface
Because CMM motion controllers are designed to perform similar operations (move and measure), most accept a generally similar set of commands and parameters. The command syntax, as well as the communication protocol, can vary widely from controller to controller. The Modular Controller interface creates a common structure - in essense a mini, internal API - capable of supporting many types of 3 to 6 axis controllers. Multiple instances of possibly dissimilar controllers are supported for multi-carriage operation.

bullet3.gif DME Control Code
This developer-supplied equipment control code is unique to each company's DOT equipment implementation. This code is called via the Modular Controller Interface, and handles all communications with the DME controller - whether by serial port, ISA/PCI bus, TCP/IP sockets, or other hardware configuration. In addition, this module can control other parts of the inspection hardware if they are not handled by the controller - such as wrist motion control via the serial port, tool changers, etc.

bullet3.gif Driver Classes
The three most common ways to interface to a controller are serial comm, TCP/IP sockets, and vendor-supplied device driver or DLL. The DOT Equipment plug-in contains basic drivers that can be used to send and receive text command strings to serial and TCP/IP devices; and this model can be readily extended to support other communication protocols as well.

bullet3.gif Data Compensation Algorithms
Sensor data compensation is handled in the equipment plug-in, as required by DMIS Part 2.

bullet3.gif Support Library
A library of helper classes, smart pointers, and macros is also included, to simplify managing DMIS Part 2 data, and to increase portability. Math classes supply vector arithmetic, matrix transformations, and other common operations. This library is also used in the application husk and math plug-ins.

 
 
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