Automatic Spreadsheet to I/O Schematics

The goal of any organization is to reduce cost while improving quality. In the engineering services business this means getting the correct information on drawings in an efficient manner. Some ways to achieve this goal are:

  1. Through the use of smart software tools which allow data to be entered one time and then shared by several programs.
  2. By the use of smart programs that automatically perform repetitive tasks.

For the controls side of engineering, I/O schematics must be created to show the wiring between the control system modules (PLC cards or DCS modules) and the final control devices. These drawings are generally created in these days of CAD by building base templates for each type of card used, copying over as required, and manually editing each drawing to show the correct device, wire numbers, power wiring, terminal numbers, etc. This leaves room for errors in re-typing data as well as consistency issues with the information in the I/O list. It is not unusual to have as many as 500 of these drawings for a large project.

Since it is common to build an I/O or instrument list for each job it makes sense to try and utilize this information as much as possible, entering it once and using many times. This ensures that all documents have the same tagging and description for these items. It also allows pertinent information to be added, such as, rack/slot/point, address, and card type for each device, creating a database instead of just a list. Once this is done the next step can be taken…. using an intelligent software package to automatically populate the I/O drawings with this information.

The Venture Engineering I&E group has been using AutoCAD Electrical to do just that. This package allows generation of I/O schematics from a spreadsheet format. This method uses AutoCAD’s parametric drawing features to draw the I/O module and rungs, place the control devices, determine the card type, and fill in the wire numbers, terminals, and tag information. Once the data is mapped and the project is configured (this can take time and many iterations to get the desired output), the process is started. This package can progress through multiple drawings and card types, reading data from the spreadsheet to build each drawing. Typically a drawing can be completed in less than a minute. These drawings do require further manual editing, but between 50% and 90% of the drawing can be completed automatically. This translates to time savings and an improvement in drawing information quality and consistency.

For more information, contact:
Derrek Jones
Instrumentation & Controls Manager
(412) 231-5890 x313