Using NI-VISA in Linux to address E8510a RS-232 port

[kilurb]

I'm trying to use the NI-VISA library in Linux to control the RS-232 port on an E8510a Lan GPIB controller.  The code I'm attempting to execute is below:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "visa.h"


static ViStatus status;                 /* For Checking error */
static ViSession defaultRM, instr;      /* Communications channels */

main ()
{
        status=viOpenDefaultRM (&defaultRM);
        if (status < VI_SUCCESS) {
                printf("Could not open a session to the VISA Resource Manager!\n");
                exit(EXIT_FAILURE);
        }
        status = viOpen (defaultRM, "TCPIP0::xx.xxx.xxx.xxx::COM1,488::INSTR", VI_NULL, VI_NULL, &instr);
        if (status < VI_SUCCESS) {
                printf("Cannot open a session to the device.\n");
                goto Close;
        }

        status = viSetAttribute (instr, VI_ATTR_TMO_VALUE, 5000);

Close:
   status = viClose(instr);
   status = viClose(defaultRM);

   return 0;
}

This does not work.  However, this code is valid and works just find for the GPIB addresses such as:

TCPIP0::xx.xxx.xxx.xx::gpib0,1::INSTR

Everything I've been able to find suggests that the above code should work.  It compiles and executes, but I always receive the unsuccessful message "Cannot open a session to the device.".  I've checked to make sure that the address is correct using the E5810a web tool.

Anyone who could possibly help would be appreciated. 

System is a Red Hat Enterprise 6 64-bit install:

Linux posey 2.6.32-220.el6.x86_64 #1 SMP Wed Nov 9 08:03:13 EST 2011 x86_64 x86_64 x86_64 GNU/Linux

[kilurb]

Adding to the available information, the return status of the viOpen command appears to be:

VI_ERROR_RSRC_NFOUND

According to the Programmers reference: Insufficient location information or resource not present in the system.

[KyleP]

Hi kilurb,

Are you ablet to ping that address at all? Does the controller have different modes that need to be configured for your GPIB settings?