Instrument Loop DrawingsDescription
After I posted the tip on using Excel for Engineering Drawings, a few of my friends working in the Instrumentation Area asked me if I could provide a template for creating loop drawings in Excel. I had used Excel for doing loop drawings before and decided to create a template for instrumentation engineers that they could use and tweak for generating loop drawings. This app provides a template that can be used for generating loop drawings using Excel. It uses a drawing template and a macro to produce loop drawings in the Portable Document Format (PDF) from a database of loop data. The data has details of a set of analog instruments in a plant connected to a PLC. The data and the drawing templates can be modified for different scenarios.
An advanced version of this app is available at the sister site www.XLnControl.com.
Download.xlsm file (26 KB)
(If the file gets downloaded as .zip, simply rename it to .xlsm.)
This app was built using Excel 2010. For Excel 2007 users - this app may not work by default because 2007 does not have the 'Save as PDF' feature. To get this feature, you have to download the add in from the Microsoft website at this link.
Once this is installed, the tool will work.
I would like to thank the Excel guru Mr. Zoran Stanojević for pointing out an error in the code.
How to useThe file has 2 sheets name 'Data' and 'Drawing'. The Data sheet consists of a table containing the loop details and the Drawing Sheet contrains a template for the loop drawing. Clicking the Generate Drawings button on the data sheet will run a macro that will generate one drawing for each loop in PDF format. The drawings are saved in the same folder that the Excel file resides in, with the loop name as the file name. If the macro is run again, existing files will get overwritten.
The loop configuration is as follows: The field instruments are wired to a junction box. A multicore cable connects the junction box to a marshalling strip in the Remote Instrument Enclosure (RIE). Single wires run from the marshalling strip to the IO cards of the PLC to complete the loop.
A sample loop drawing is shown below.
I have used tools like this to do work on some greenfield projects, where the use of a full fledged loop management package was not justifiable. We would call such tools ‘poor man’s loop design package’. I came across this article, where Excel has been used for loop management at a large refinery.
How it worksThe principles used in generating the drawings for different loops are the same as outlined in the tip Engineering Drawings Using Excel. In this app, a macro is used to loop through the tags in the Data sheet and generate the drawing for each loop. VLOOKUP formuale is used to pull the relevant data for each tag into the drawings from the Data sheet.
An advanced version of this tool can be purchased from the sister site XLnControl.com.