C++ Help with GPIB and 488.1 device

[shard923]

To Any and All,

Can you tell me what I am doing wrong here?

#include

<iostream>

#include

<windows.h>

#include

"ni488.h" int main()

{

int gpib;

gpib = ibfindA(

"GPIB0");

ibsic(gpib);

ibcmd(gpib,

"_?@3",4L);

ibwrt(gpib,

"C2",2L);

ibcmd(gpib,

"_",1L);

ibcmd(gpib,

"_?@3",4L);

ibwrt(gpib,

"A0",2L);

ibcmd(gpib,

"_",1L); return 0;

}

The device does not respond to myt commands. I think it is probably with my board initialization, but I am at a loss. I know the commands work with ibic.exe, in the order presented and the hardware and unit are working. So it must be my coding.

If I use ibfind I get this error;

error C2664: 'ibfindW' : cannot convert parameter 1 from 'const char [6]' to 'LPCWSTR'

1> Types pointed to are unrelated; conversion requires reinterpret_cast, C-style cast or function-style cast

[muellerp]

Hi,

what is the returned status

status1=ibsic(gpib);

status2=ibcmd(gpib,"_?@3",4L);

status3=ibwrt(gpib,"C2",2L);

...

?

Hint: You can check the returned status variables (if not 0) with the GPIB error coding list. If the stuff works fine, status should be 0.

Best regards peter

[RayFarmer]

Hi,

You should use ibfind() but if you are going to use ibfinda() then you need to pass a value of type LPCSTR, therefore you need to cast "GPIB0".

also you should also capture the return values so you can handle the error conditions

Regards

Ray Farmer

[shard923]

muellerp,

I just got in this morning, but give me a little bit and I can get you the return values. I will either attach the NI Spy or re-write my code to capture the values.

Message Edited by shard923 on 01-16-2008 07:48 AM

[shard923]

Ray Farmer,

What the heck is that LPCSTR and how do I cast to it. Do I just do a <static_cast>LPCSTR ? Is that some sort of Microsoft data type? Thank you for your help.

[RayFarmer]

Hi,

You can declare a variable ie

LPCSTR device = "GPIB0";

gpib= ibfind(device);

or

gpib = ibfind ((LPCSTR)"GPIB0");

regards

Ray Farmer

[shard923]

Ray,

When I use

gpib = ibfind(LPCWSTR(

"GPIB0"));

the project will compile but then NI Spy tells me that iberr is EVDR, or "Error connecting to driver or device" and then all the following commands then fail.

[shard923]

muellerp,

I looked at the script with NI Spy and it told me all commands went through okay except my ibwrt. A coworker here had changed the PAD of the GPIB0 to 25 instead of 0, so the ibwrt wasn't working. Thank you for your help. I also found that despite what the manual and programming instructions say for the units I am working with, the "B" model and the "C" model are different in how they react to IEEE commands.

[ninno]

To shard923:

I'm quite interested in the work you are doing on ADT-222B. Would you please contact me directly - that_mail@yahoo.com

Thank you,

[shard923]

Ray,

I ended up fixing this by using a multi-byte character set in the properties drop-down of the project menu. After that, ta-da, no complaints from the compiler.