C# Visual Studio GPIB Commands

Question

What commands do you use to talk to a GPIB instrument in C#, visual studio? I need to be able to write commands to the instrument and read the output.

Answer 1

I use Agilent IO Library Suite.

Here is a tutorial to use it on C#: I/O programming examples in C#

Nevertheless, in my company we had stability issues with the VISA-COM implementation, so we wrote our own wrapper around the visa32.dll (also part of the IO Library suite) using P/Invoke.

(Disclosure: I work in a company that make intense use of GPIB instruments)

Answer 2

I'm using National Instruments VISA and NI 488.2.

First make sure that you checked the VisaNS.NET API in the NI-VISA Setup, see the following figure:

Add a reference to NationalInstruments.VisaNS and NationalInstruments.Common to your project.

Create a MessageBasedSession, see the following code:

string resourceName = "GPIB0::20::INSTR"; // GPIB adapter 0, Instrument address 20
var visa = new NationalInstruments.VisaNS.MessageBasedSession(resourceName);
visa.Write("*IDN?"); // write to instrument
string res = visa.ReadString(); // read from instrument

A MessageBasedSession can be used to communicate with your instrument over GPIB, Ethernet or USB.

Update

Ivi.Visa superseded NationalInstruments.VisaNS. So you should add a reference only to Ivi.Visa to your project.

The example would look like that:

string resourceName = "GPIB0::20::INSTR"; // GPIB adapter 0, Instrument address 20
var visa = GlobalResourceManager.Open(resourceName) as IMessageBasedSession;
visa.RawIO.Write("*IDN?\n"); // write to instrument
string res = visa.RawIO.ReadString(); // read from instrument

The benefit of using Ivi.Visa is that it works with one of the following libraries:

• National Instruments VISA
• Keysight IO Libraries Suite
• Rohde & Schwarz VISA