A few days ago I updated the Mathcad files that link to the Prode Physical Properties (PPP) program. In this post, I want to discuss the different kinds of PPP updates and how they affect the Mathcad updates.
Three kinds of PPP updates
When Prode updates their program, there are three kinds of files that might be changed:
What PPP update requires an update of the Mathcad-PPP files?
Item 2 is the only update that affects the prode.dll and the Test-PPP.xmcd files.
What happens when you download a new version of PPP?
When you install a new version of PPP, the install program places the latest version of ppp.dll in the appropriate system folder, and it places the reduced chem.dat file for non-subscribers in the Program Data/prode folder. If item 3 was not updated, a user with a paid license then copies their old, full chem.dat file into that folder, along with their old license.dat file. If item 3 is updated, licensed users receive an email with the new chem files and a new license.dat file. If the ppp.lib file was updated, it will arrive with the download, but that file is not used directly by Mathcad users. Instead, I use that file to create the prode.dll files for Mathcad and Prime.
Can you run a new version of PPP without a corresponding update of the prode.dll?
Yes you can! Any changes to ppp.dll and chem.dat are unaffected by the library functions. Until the prode.dll for Mathcad is updated, your old programs can still be used with the old calling formats. Any new functions in the new library will not be available.
When you update with the prode.dll found on this site, will your old programs still run?
That depends upon whether your program uses a function that has changed. For example, the recent update changed the mc_MixF function because the ppp.lib file changed the MixF function. The old version of that function would produce an error. When you see the error, you should check the Test-PPP.xmcd file to see the new calling format and a description of the arguments.
Another way to check for all of the function changes is to install the new prode.dll and then run the old Test-PPP.xmcd file. All functions that have changed will have errors and be in red. Then look in the new Test-PPP.xmcd file for the new formats.
My motivation for this post
Basically, I feel a little guilty for waiting so long to update the prode.dll and test files for the PPP version 1.2c3. However, I wanted to explain that the delay wasn't preventing users from running Mathcad-Prode with new chemical data or preventing them from running completely. All that was delayed was use of a new version of MixF.
If you are unfamiliar with PPP...
I think the Mathcad-PPP combination is one of the most cost effective general purpose computation tools for chemical engineers. The archives of this blog demonstrate many examples of its use. To see the extensive, yet easy to use functions, and the kind of data available, you may download the pdf file of the Test-PPP.xmcd. Click on the button below to go to the page where that file resides.