Has Recent Work Introduced Errors?

You may have read this analysis of the errors DBDOC found that had been introduced into a client system over four years.

Here is another summary analysis of the important errors introduced into a different system over five years. DBDOC makes this sort of analysis trivial if you have backups of systems before and after work is done. Here are questions that should be asked:

1. How many errors that could hurt the plant are acceptable?
2. Why were these errors not in front of the DCS team for evaluation?
3. How could these errors, all breaking the rules, yield a clean Composer compile?
4. Should Composer have caught them?

Duplicate ADAPT Blocks and Multiple TSTALM Blocks

There are ten errors that result from the failure of Composer to force a cloned ADAPT or TSTALM block to have S2 or S1 set to -1 when the block is cloned.

Two of these errors are shown below. It is absolutely clear that S2 of block 1060 and S1 of block 1066 both should be 1062, not 2450. The value 2450 is residual from the working logic that was cloned into this logic. This is typical of a class of error made again and again by Composer users.

The block index for the prototype MSDRVR FC 129 Block 1062, centre of a wonderful set of beautiful functioning logic. The highlights show the four extra TSTALM block errors, so there are six of each. Not one of the errors was found when the work was done, compiled by Composer or loaded by the user.

Some Function Blocks are Defaulted as Disabled

This error message shows that one lag function was not enabled when it was added. The effect would show up as inexpicable unintended excursions that are supposed to be smoothed out. Clearly, the default should be to be enabled, not disabled.

Specification out of Range

What does this block do?

We could guess. Why should we have to? Why is this not an error in Composer, as the only legal values are 0, 1 or 2?

TSTQ Tests Block With No Quality

The work being analyzed has only two errors where a block is being tested for quality when it does not have quality to test. Only two!

First, note how the blocks with quality, shown by DBDOC as blue lines, lose that attribute when they go through logic blocks. Here, the cost of the one second lag function is the loss of quality for the pressure signal.

So, bad quality on the pressure signal will not be detected. What is it supposed to do? Simply put the FLOW CONTROL STATION into Manual. Oops!

Summary

There are fourteen potentially significant errors documented here, with many more less severe not mentioned. They should not have been made, and they should have been caught.

Analysis: DBDOC Detects Four Years of Introduced Errors

This is a summary analysis of the important errors introduced into a system over four years. DBDOC makes this sort of analysis trivial if you have backups of systems before and after work is done. Here are questions you should ask.

1. How many errors that could hurt the plant are acceptable?
2. Why were these errors not in front of the DCS team for evaluation?
3. How could these errors, all breaking the rules, yield a clean Composer compile?
4. Should Composer have caught them?

Error Browser Presentation

The builds of 2010 and 2014 versions of the Composer project show 49 significant errors that were left in the system after the work was commissioned. DBDOC shows "new" errors highlighted and allows you to focus on them. Old ones are important, too, but good work should not introduce new ones. After all, Composer is two decades old now and ought to be counted on to protect the users.

Some Function Blocks are Defaulted as Disabled

This error message shows that one lag function was not enabled when it was added. The effect would show up as inexplicable unintended excursions that are supposed to be smoothed out. Clearly, the default should be to be enabled, not disabled.

Looking at two of these messages (for Blocks 3678 and 3679), it is absolutely clear that the plant is not protected by rate limiter blocks (FC8) that were inserted to limit the rate of change. The red warning triangle shows the one we clicked on above. The yellow triangle (called an error marker) would also be visible, and you would see when you got to the logic in your analysis or troubleshooting.

TSTQ Tests Block With No Quality

The work being analyzed has thirty-seven errors where a block is being tested for quality when it does not have quality to test. None of that logic does what it is intended to do.

First, the simple error is clear. Testing quality on an output if a FC 80 M/A MFC/P block simply makes no sense. It does not work. The green arrow shows the erroneous test being carries out.

However, as is often the case, finding bad work makes you look at the intent of the logic. What was intended here?

It appears that either U1 ID FAN SUC PRESS BQ or ID MASTER IN AUTO is supposed to replace ID MASTER DEMAND with 100.0. That will not happen!

Summary

There are forty-nine potentially significant errors documented here, with many more less severe not documented. They should not have been made, and they should have been caught.

DBDOC 10.7 -- Download Your DBDOC Update Today!

We are delighted to announce the release of DBDOC 10.7, with a variety of upgrades, bug fixes, and new features.  A few of the major improvements are noted below.  For more information, please see What's New and the Release Notes.

Built-In PDF Files

If your system contains PDF file documentation, you will be happy to learn that PDFs are now first-class citizens in DBDOC, built directly into the M14 like other document types.  They can be viewed right inside of Hyperview, links to blocks and tag references are made automatically, and they can be searched like other documents.

Links to external PDF documentation are still supported, too.

See Built-In PDF Files and More! PDF File Support in DBDOC 10.7 for more information.

Configuration Change History Support

DBDOC 10.6.1 introduced the creation of DMPCFG files for both the .CFG files and the CLD and CAD sheets automatically when you do a DBDOC build.   DBDOC 10.7 introduces automatic archiving of the files from both the CLD / CAD sheets and the compiled or saved CFG files. When you do your DBDOC build, your DMPCFG files will now be archived with the error files. Also, the last build you did before installing 10.7 will be archived. Thus, you will start with a base for comparison of the last build you did with DBDOC 10.6.1 and the first with DBDOC 10.7.

See Configuration Change History Support in DBDOC 10.7 for more information.

Improved S+ and 800xA PG2 Graphics and MicroStation Drawings.

Display of S+ graphics has been significantly improved. Symphony Plus graphics rendering has been greatly improved. Splines, background colors, lines, etc. which previously were not drawn, now appear, and previously handled elements are now drawn more accurately.  The user can now also specify the path to their Symphony Plus image files in Wizard so that Hyperlink can find and use the correct image specified in a graphic. S+ and 800xA live data display sizing has also been improved. MicroStation drawings have improved text display, rendering and remove duplicate search hits.

Improved Error Detection

Processing has been extended to check more blocks for continuous exception reports.  The use of PID and APID blocks with derivative gain combined with inputs from discontinuous input blocks is reported.

See examples of these errors and the problems they cause here.

"Lost Project" Recovery

DBDOC 10.7 can recover "lost" projects. A feature to recover "lost" projects has been added to BuildPlus, allowing project recovery if are inadvertently "lost" due to a change in UAC level on a machine or a user's privilege level.

There's more...

For more information, please see What's New and the Release Notes, or follow this blog, where we will be illustrating new features and DBDOC capabilities regularly.

Click here to get your DBDOC 10.7 Update now!