How to read data as long as there is new data in buffer?

Hello

I'm working on controlling keithley2400 to measure the I-V character.

The test need receive a lot of data.

Now,my way todo this is to set a delay time .

When I send all my orders to 2400,delay 10000ms,then it begin to measure.

I think the measure way is not convenient.

(Qt 5,VISA)

In the past measure I use readyread signal which is a signal in QSerialPort ...That's is conveniet but it does't support GPIB or others.

Thanks for all.