Serious Performanc​e hit on RT (cFP 2120) using LV 8.5 compared to LV 8.2

Question

Hello,
We have just finished a large project using LabView 8.2 and Compact FieldPoint (cFP) 2120 on a Windows XP Pro computer.
The system developed controlled equipment that forms critical parts of a Concrete Plant here in Norway.
2 Identical units whre installed controlling two almost (but not entirely) identical pieces of equipment.
The project has been a great success, and used technologies such as: StateDiagrams (StateDiagram Toolkit) to describe the System Processes, Network Shared Variables to transfer approx. 50 different  pieces of non-critical information over WLAN to a LabView based Surveillance Program in a Control Room from both "machines".
The CPU Load on the cFP was approx. 65 % which gives the ETS Realtime OS (RTOS) plenty of "room" to run its "maintenance threads".
After the last installation, we decided to try to migrate the system to LabView 8.5 on another Computer running Windows Vista. The system ported nicely and run on our test cFP 2120 as well.
We had done extensive performance / cPU Load tests on our 8.2 system, and new that in a particular setting the CPU Load was:
  *** 65% *** measured using the System Manager (disabling VI and Memory Monitioring).  (Absolutely max measured is 71 % when the system is running)
When we did the same test on the cFP running the LV 8.5 compiled code and with the LV 8.5 software installed on the cFP, we where in for a chock:
The CPU Load was *** 87% *** in the particular setting, and could run over 90%.
This renders LV 8.5 useless for our controll task. A setback, as we had plan to port our current code using the Statechart Module that we had bought for LV 8.5.
We also installed a VI to "Monitoring the CPU Usage of a LabVIEW Real-Time Target" found at this link:  http://zone.ni.com/devzone/cda/epd/p/id/4713
It turns oot that this VI gave us the same result as using the "System Manager" (if we summed the load for each priority), but also gave more info about the load at each priority.
We of course did not run the System Manager at the same time, as this would cause a conflict: We either run the System Manager or the VI above. When the System Manager was run, the Vi above was
disabled !
We are running updating of the 50 Network Shared Variables in a Normal Priority Thread. The 9 StateDiagrams are each running in a Separate Thread started by including the VI for the StateDiagram in a  Timed Sequence with one frame: This gives all these Processes "Very High" Priorty and you can see that most of the work is done at this priorty level. The Very High Priorty level uses Single Process  Shared Variables with FIFO to send the variables to the Network Shared variables in the "Normal Priorty" Thread.
The Shared Variabel Server is run on the PC in the Control Room and not on the cFP.
Below you can see the Installed Components and the Performance Result for the cFP when Running configured for LV 8.2 and 8.5.
For LV 8.5, the performance of each Priority Level is degraded with the same percentage (approx 30%) which is really serious.
National Instruments Engineers: Please help identify / fix this problem and give us a Time frame for when the problem can be fixed!
LabView 8.2 Installed Components on cFP 2120:
http://objective.no/gostemp/cFP_Components_LV_8-2.​jpg
LabView 8.2 cFP 2120 cPU Load:
http://objective.no/gostemp/cFP_LV_8-2_CPU_Load.jp​g
LabView 8.5 Installed Components on cFP 2120:
http://objective.no/gostemp/cFP_Components_LV_8-5.​jpg
LabView 8.5 cFP 2120 cPU Load:
http://objective.no/gostemp/cFP_LV_8-5_CPU_Load.jp​g
regards
Geir Ove Skjærvik
Objective Technology
Norway
Geir Ove

Answer 1

Hello,
I have reproduced the problem in a minimalistic test application !
Download the test from this link: http://objective.no/gostemp/lv_8_5_probleml.zip
This is how the test looks: http://objective.no/gostemp/LV-8-2_8_5_Test_01_vi.​jpg
The ZIP file contains the following files:
a) LV-8-2_8_5_Test_01.vi    -  The test VI itself
b) SK1_Host_Remote_Panel_Shared_Variables.lvlib   -   The Network Shared Variables that I use only one of in this test (SK1_Error_Code)
c) Interprosess_Data.lvlib  -  The Single Process Shared variables that I use only one of in this test (Reported_Error_Code)
I have not included a Project File and you need a Compact FieldPoint to test this. I have a cFP 2120.
Now to the intersting figures:
Compiled under LabView 8.2 this application runs with 21 % CPU Load as measured by the System Manager on the cFP 2120.
Compiled under LabView 8.5 this application runs with 42 % CPU Load as measured by the System Manager on the cFP 2120.
This is a dramatic degradation of Performance !
I have not yet investigated if removing the Shared Variables will change this.
NI: Please Help locating this problem !
The only thought I have is this: Does LV 8.5 take care of the change of the Shared variables when the two .vlib libraries are moved to a 8,5 project ?
Geir Ove