ibwrt/ibrd read and write speed

[AmeshB]

Hi,

I am using ibwrt/ibrd to communicate with GPIB bus. It takes more than 20 miliseconds to perform read and write from the bus.

Is there any way I can improve this speed? I want to read/write with minimum 1milisecond.

Any suggestions?

Umesh

[Wolfgang]

While GPIB itself is fast, typical communication with instruments is slow due to handshaking. So as soon as you change from read to write and vice verse things slow down significantly.

Also, speed depends on the instrument.

For example, reading a waveform from a scope of company A versus scope of company B has given me differences by a factor of 3 to 5 (identical GPIB board/cable, identical number of data points transferred) 

[AmeshB]

Thanks for your comments. I would like to know about the reading speed of the GPIB with ibrd function.

In my application, I have found that, to read data of 64 characters, ibrd function takes more than 20 millisecond.

Is there any other way, I can get this data with faster rate, say with 1 millisecond?

Umesh

[AmeshB]

Thanks for your comments. I would like to know about the reading speed of the GPIB with ibrd function.

In my application, I have found that, to read data of 64 characters, ibrd function takes more than 20 millisecond.

Is there any other way, I can get this data with faster rate, say with 1 millisecond?

**************************************************************************

For your reference, below is the code from my application,

// GPIB read
ibrd (pZg->device, pZg->gpibReadData, ZYGO_STRING_SIZE);

// get GPIB status code and check for GPIB Error
    pZg->gpibStatusCode = ibsta;

    if (ibsta & ERR)
    {
        pZg->gpibErrorCode = (unsigned int) iberr;
        strcpy(pZg->gpibErrorMessage,GpibErrorMessage());
        return ZYGO_ERROR;
    }

 pZg->gpibReadData[ibcntl] = '\0'; // null character

**************************************************************************

Umesh

[JL@NI]

Hello Umesh,

What is the controlling GPIB card and which device are you communicating with?

Thanks,

Jeff L.

[AmeshB]

Hi,

We are communicating with the Zygo control board 8030 (ZMI 2000). And we are reading data of the ZYGO laser. Only problem is the reading speed is 20 milliseconds per read. I am not able to find why ibrd is taking more than 20 Millisecond to read data (256 characters) from the device.

Thanks,

Umesh

[JL@NI]

Hello Umesh,

Do you notice the same behavior in the GPIB Interactive Control?

Regards,

Jeff L.