PXI-2527 with C++

[einszweidrei456]

Hello,

i have a problem with. I try to controll a PXI- 2527-switch by using c++ and I`m not very familiar with the subject. This is my code so far:

#include "stdafx.h"
#include "niswitch.h"


int _tmain(int argc, _TCHAR argv[])

{
    ViSession Name = VI_NULL;
    ViRsrc MUX = "PXI15::14";
    ViConstString channel1 ="ch0";
    ViConstString channel2 = "com0";

    ViConstString topology = NISWITCH_TOPOLOGY_CONFIGURED_TOPOLOGY;

    niSwitch_InitWithTopology(MUX, topology, VI_FALSE, VI_TRUE, &Name);

    return 0;
-------------------------------

If I try to build this I got an error massage:

error LNK2019: unresolved external symbol "_niSwitch_InitWithTopology@20" in Funktion "_wmain".

But the function "niSwitch_InitWithTopology" is defined in the included header "niswitch.h".

Can somebody tell what I did wrong?

Thank you.

Peter

[JoLe]

Hi,

this looks like you did not tell your development environment where to find the header file.

Follow these steps:

Using NI-SWITCH in Visual C++

http://zone.ni.com/reference/en-XX/help/370388Y-01/switch/niswitch_c/

I hope this approach will solve your problem with the linker.

Best Regards,

JoLe

National Instruments

Applications Engineering

www.ni.com/support

[einszweidrei456]

I don´t think that is the problem. Visual Studio has a seperate massage for an unlinked header. I´ve got that earlier. Maybe it is a Problem with the "niswitch.lib". I´ve linked it too but it isn´t included in the code.

[JoLe]

Hi einszweidrei456,

disregarding you dont think that this is the problem, have actually tried to apply this step?

Specify the directory that contains the NI-SWITCH header file under the Preprocessor»Additional include directories settings in your compiler—for Visual C++ 6.0 these files are under Project»Settings»C/C++. The NI-SWITCH header files are located in the .\Include directory within your NI-SWITCH directory.

Add the NI-SWITCH import library niswitch.lib to the project under Link»General»Object/Library Modules. The NI-SWITCH import library files are located at IVI\Lib\msc.

Do you still get the error after applying this?

Best Regards,

JoLe

National Instruments

Applications Engineering

www.ni.com/support

[einszweidrei456]

Hi JoLe,

I still get the error.

I have added the following directories under "Project - Properties - C/C++ - general - additional include directories":

IVI Foundation\VISA\Win64\Include

and

IVIFoundation\IVI\Include.

They both contain "niswitch.h" and a lot of other headers like "niswitchTopologies.h" and "visa.h". (They don´t contain the "niswitchErrorHandler.h")

The .lib directory is added under

"Project - Properties - Linker - general". The directory name is "IVIFoundation\IVI\Lib_x64\msc".

Thank you

einszweidrei456

[einszweidrei456]

Hi JoLe,

I have found my mistake. I have tried to build a 32bit-programm with a 64bit-library. Now the programm is compiled but it still doesn´t work. In the example code is the line

ViSession  switchSession=VI_NULL

and I think VI_NULL is not the right parameter for my Session(, or is it?). Where can I get the right one?

Thank you.

Peter

[JoLe]

Hi einszweidrei456,

great to hear, that you could fix the error with the library!

What you are asking now is a bit too unspecific to really know what you are doing and hence expecting.

- what exactly does not work?

   - what are you doing? Are you trying to do a switching operation with existing hardware, which one?

   - how is your code looking meanwhile?

   - what do you expect your code to do?

   - What should work, what do you expect to observe?

- You write "in the example code"

On which example do you actually build up your code?

- if you look to the examples which are delivered with the NI-Switch driver (C:\Program Files (x86)\IVI Foundation\IVI\Drivers\niSwitch\Examples\C), you will find this line in each of the examples:

ViSession switchSession = VI_NULL;

This is the initial value for this parameter. VI_NULL in the NI-Switch driver is the same as the usual NULL parameter in C++

In the following example code, you can see, that if the parameter switchSession has a different value from VI_NULL, it is an error case and the session to the switching hardware is closed.

/*

 National Instruments - NI-SWITCH - CVI Examples

 Controlling an Individual Relay

 This example demonstrates how to control an individual relay on a switch module.

 Refer to the NI Switches Help for the valid relay names for your switch module.

 NI-SWITCH functions utilized:

 niSwitch_InitWithTopology
 niSwitch_RelayControl
 niSwitch_WaitForDebounce
 niSwitch_close

*/


#include "niswitch.h"
#include "niSwitchErrorHandler.h"

int main (void)
{
   ViSession switchSession = VI_NULL;
   ViStatus switchError = VI_SUCCESS;
   ViRsrc resourceName = "Dev1";
   ViConstString relayName = "b1r0c0";
   ViInt32 relayAction = NISWITCH_VAL_CLOSE_RELAY; //NISWITCH_VAL_OPEN_RELAY to open relay.
   ViConstString topology = NISWITCH_TOPOLOGY_CONFIGURED_TOPOLOGY;

   //Open a session to the switch module and set the topology.
   niSwitchCheckErr(niSwitch_InitWithTopology(
      resourceName,
      topology,
      VI_FALSE,
      VI_TRUE,
      &switchSession));

   //Open or Close the relay.
   niSwitchCheckErr(niSwitch_RelayControl(
      switchSession,
      relayName,
      relayAction));

   //Wait for the relay to activate and debounce.
   niSwitchCheckErr(niSwitch_WaitForDebounce(switchSession, 5000));

Error:

    if (switchError < VI_SUCCESS)
    {
       //Display errors (if any).
       niSwitch_ErrorHandler(switchSession, switchError);
    }
    if (switchSession != VI_NULL)
    {
       //Close the session to switch module.
       niSwitch_close(switchSession);
    }
    
    return 0;
}

[einszweidrei456]

Hi,

i just want to connect and disconnect 2 channels on my PXI2527. This is the code that i have build to an .exe and it seems that the exe works but the switch doesn´t make the connections and I don´t see why not?

#include "stdafx.h"
#include "niswitch.h"


int _tmain(int argc, _TCHAR argv[])

{
    ViSession Name = VI_NULL;
    ViRsrc MUX = "PXI15::14";
    ViConstString channel1 ="ch0";
    ViConstString channel2 = "com0";

    ViConstString topology = NISWITCH_TOPOLOGY_CONFIGURED_TOPOLOGY;

    niSwitch_InitWithTopology(MUX, topology, VI_FALSE, VI_TRUE, &Name);

    niSwitch_DisconnectAll(Name);

    getchar();

    niswitch_connect(Name, channel1, channel2);

    getchar();

    niSwitch_disconnect(Name, channel1, channel2);

    getchar();

   

    return 0;

Thank you.

Peter

[JoLe]

Hi Peter,

please refer to the following example (delivered with the NI switch driver) to connect the channels of your switching modul. 

You will find these examples in

C:\Program Files (x86)\IVI Foundation\IVI\Drivers\niSwitch\Examples\C (for a 64-bit machine)

Please post if deploying this code did work on your system.

Best Regards,

JoLe

National Instruments

Applications Engineering

www.ni.com/support

/*

 National Instruments - NI-SWITCH - CVI Examples

 Making Connections on a Switch

 This example demonstrates how to connect channels on a switch module.

 Refer to the NI Switches Help for the valid channel names for your switch module.

 NI-SWITCH functions utilized:

 niSwitch_InitWithTopology
 niSwitch_Connect
 niSwitch_WaitForDebounce
 niSwitch_close

*/


#include "niswitch.h"
#include "niSwitchErrorHandler.h"

int main (void)
{
   ViSession switchSession = VI_NULL;
   ViRsrc resourceName = "Dev1" ;
   ViConstString channel1 = "r0";
   ViConstString channel2 = "c0";
   ViConstString channel3 = "r1";
   ViConstString channel4 = "c1";
   ViStatus switchError = VI_SUCCESS;
   ViConstString topology  = NISWITCH_TOPOLOGY_CONFIGURED_TOPOLOGY;

   //Open a session to the switch module and set the topology.
   niSwitchCheckErr(niSwitch_InitWithTopology(
      resourceName,
      topology,
      VI_FALSE,
      VI_TRUE,
      &switchSession));

   //Connect channel1 and channel2.
   niSwitchCheckErr(niSwitch_Connect(switchSession, channel1, channel2));

   //Wait for any relays to activate and debounce.
   niSwitchCheckErr(niSwitch_WaitForDebounce(switchSession,5000));

   //Connect channel3 and channel4
   niSwitchCheckErr(niSwitch_Connect(switchSession, channel3, channel4));

   //Wait for any relays to activate and debounce.
   niSwitchCheckErr(niSwitch_WaitForDebounce(switchSession,5000));


Error:

   if (switchError < VI_SUCCESS)
   {
      //Display errors (if any).
      niSwitch_ErrorHandler(switchSession, switchError);
   }
   if (switchSession != VI_NULL)
   {
      //Close the session to switch module.
      niSwitch_close(switchSession);
   }

   return 0;

}