rt modbus on cFP, shared variables, error -1950679035

[Corny]

Hey,

Ive made a realtime application that runs on a cFP 2120 and reads from an modbus slave device connected to a seriell port on cFP. I use a ModBUS master IO server on the cFP that is set to communicate with my device, and have created shared variables that are binded to this server.

The goal is to read coils, input registers and holding registers from my device. In a small application with a few shared variables (binded to each modbus register) it all works perfect and I'm able to read from my device without problems. In my larger application I use around 100 shared variables that are binded to the modbus IO server and modbus registers, I get error: -1950679035 at some shared variables (mostly input registers).

Error -1950679035 occurred at ni_tagger_lv_Read

Possible reason(s):

LabVIEW:  (Hex 0x8BBB0005) Unable to locate variable in the shared variable engine.  Deployment of this variable may have failed.

(even when all variables are deployed successfully at the cFP)

Things Ive tried to solve this:

- rename the shared variables (it works for a small period of time, untill many are renamed and im back to where I started)

- delete and create new shared variables (works, but suddently it doesnt work anymore)

- change the shared variable (enable/disable buffering, data type, etc..) (gives the same effect when changing its name)

- do all other stuff that really is unexplainable to get it to work, but worth trying since I havent found a solution.

- Format the entire cFP, and reinstalled all software at it (LV RealTime 8.0.1; network variable engine 1.0.0; Modbus IO server 1.0.0; etc)

Anyone knows how to get rid of this error message, or knows a solid workaround? Anyone has used the modbus IO servers on the cFP and has experience using shared variables that are binded to this IO server?

my conclusion is that there is a bug that crawls somewhere in the rt/variable engine on cFP?

Also does anyone knows how to view what shared variables are loaded into the shared variable engine at the compact fieldpoint?

Thanks in advance!

[DG3005]

Hi Corny,

I'm also getting error code -1950679035. Instead of modbus , we 're using inat in order to communicate between LV and OPC.

Anyway the problem is as you described.

If you click on the shared variables -->visible items-->label you will find a project explorer like path instead of an absolute path. So just imagine you are copiing your shared variable library"abc" , so that you have 2 of it. When observing the variables in the Variable Monitor, it will only appear one library"abc" but not the other one. The user doesnt come to know to which library it is refering.

Just imagine to access an application through a network. Which library will be used by your national instruments "Variable Monitor".

To put it breafly, the application does work correctly despite this error 1950679035, when clicking ok in the Dialog box. The only thing is that LabVIEW8.0X doesn't know which library to use, when there are several libraries with the same name. 

So my questions is : is there a clean solution or any workaround ; or how to suppress this error ( .. it is allowed to suppress this because it is working fine anyway. )

Kind Regards   

DG3005