Keithley 2420 GPIB LabWindows CVI SCPI/Driver help

[ArashE]

Thanks for the fast reply. So I am trying to just write the codes without the driver. First, I would like to initialize the device. Should I do that via the VISA commands, or ib commands? So far I have this:

VM = ibdev (0, 7, NO_SAD, T10s, 1, 0);     //Nano Volt Meter
if (iberr != 0) return iberr;
Csrc=ibdev (0, 23, NO_SAD, T10s, 1, 0);  //Current Source
if (iberr != 0) return iberr;
MUX = ibdev (0, 10, NO_SAD, T10s, 1, 0);   //MUX
if (iberr != 0) return iberr;

.

.

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When I execute this as the beginning of my initialization, I get a NON FATAL RUN TIME ERROR, iberr = 7. I looked that error up and it says that "The GPIB interface board does not exist, its driver is not loaded, or it is not configured properly." However, I can communicate with this device via MAX and there is no problem. But I noticed that MAX uses VISA commands. So what am I doing wrong that I can't connect to this device in CVI?

[ArashE]

How can I get my instruments' handles? I need that to write commands with VISA

[Swathi B]

Hi ArashE,

If you are looking to implement VISA communication, I would suggest looking at some of the shipping examples. You can locate these within the NI Example Finder from LabWindows CVI (Help»Find Examples) and access other C source code files from Start»Programs»National Instruments»VISA»Examples.

[dcl9000]

Keithley 2420 is the high power version of Keithley 2400.  Following partial codes are what I use to control Keithley 2400 through GPIB.

You should be able to modify the codes for your application.

//---------------------------------------------------------------------------------------------------------------------------------------------------

#include <utility.h> 
#include <formatio.h>
#include <gpib.h>
#include <ansi_c.h>
#include <cvirte.h>    
#include <userint.h>
#include <cvirte.h>    

#define GPIB_card              0

#define KE2400_GPIBaddr      19

static int KE2400Sweep;        // the user panel

char set_state_cmd[200], str_buffer[100];

double IV[5];

int main (int argc, char *argv[])
{
   if (InitCVIRTE (0, argv, 0) == 0)
      return -1;  /* out of memory */
   if ((KE2400Sweep = LoadPanel (0, "KE2400_rev.uir", PANEL)) < 0)
      return -1;
  
   if (SUCCESSFUL!=OpenKE2400())
      return -1;
  
   DisplayPanel (KE2400Sweep);
   RunUserInterface ();
   DiscardPanel (KE2400Sweep);
   return 0;
}

int OpenKE2400(void) //initialize source meter
{
   short dev_ready = FALSE;
   char message[50];

   KE2400 = ibdev(GPIB_card, KE2400_GPIBaddr, 0, T10s, 1, 0);
   ibln(KE2400, KE2400_GPIBaddr, NO_SAD, &dev_ready);

   if ( dev_ready != TRUE )
   {
      sprintf(message, "KE2400 Source meter is not ready!");
      MessagePopup ("Device Error", message);
      return -1;
   }
   else
      return SUCCESSFUL;
}

.............

//set source meter to souce voltage, reading current, and set compliance current
Fmt (set_state_cmd, "%s<:Sens:Func:Conc Off;:Sour:Volt:Rang:Auto On;:Sour:Func Volt;:Sens:Func 'Curr:DC';:Sens:Curr:Prot %f\n", compI);

ibwrt (KE2400, set_state_cmd, strlen(set_state_cmd));

//set source voltage value, and turn output on

Fmt (set_state_cmd, "%s<:Sour:Volt %f;:Sour:Del 0.1;:Output On\n", presentV); 
ibwrt (KE2400, set_state_cmd, strlen(set_state_cmd));

...............

ibwrt (KE2400, ":Read?\n", 6);                 //read results from source meter 
ibrd (KE2400, str_buffer, 99);  
Scan(str_buffer, "%s>%5f[x]", &IV);        //save results in an array

//------------------------------------------------------------------------------------------------------------------------------------------------------------------------