Safe Programming Practices

Code Samples and Tips
1

Dear Sir:

  I am used to writing programs where I have some degree of control over how much I occupy the PC computer's operating system time.    In other words, if my program (PAC Display Runtime) is running on a Windows 7 operating system I don't want my program to task the O/S so frequently that it interferes with the proper operation of other programs which may be running at the same time.  

  I would like to know how PAC Display communicates with the O/S.   Specifically, is a PAC Display program automatically configured to be an event driven program?

  Also, I would like to be introduced to programming techniques which will result in my programs communicating with the O/S as little as possible.   Can you please tell me the best techniques to accomplish this goal?
2

How and how much PAC Display uses the CPU/OS will vary widely depending on a number of factors, including which features you’re using in PAC Display. I strongly encourage you to read this Performance Tech Note (for 1776) and experiment with the task manager to see how the features and settings you’ve chosen affect your CPU usage, etc.

There’s also this Best Practices Tech Note which takes a higher-level look at putting together your system.

-OptoMary

3

Dear Mary;

Given the fact that the OPTO22 processors uses a round robin system, in your professional opinion, would you say that it would be nearly impossible for the OPTO22 system to burden other external programs to the degree where they fail to operate correctly running under Windows 7 (let’s say the PAC OPTO processor program is small running less than 3 charts and the Display Runtime has only a small number of user inputs)?

4

Given the size and complexity of the system you mention, my opinion/guess would be you’re not pushing anything (Windows or PAC) enough to worry about.

You could easily prove this to yourself by using Windows Task Manager’s Performance tab over time with everything running.

5

Dear Mary;

   Thank you for your reply.  

   I composed this post because verification from technical support aids in my understanding of your system.  I don't like to theorize about system performance when I can't see all the code, or I am unaware of all the events that are taking place in the background of a PC.   A reply from you is greatly appreciated.  

   By the way, sometimes I compose posts that I feel I should delete entirely from your website.   Can you please tell me if this is possible?

   Thanks for your great reply.

   Sincerely,

   Michael