Keithley 2700 RS232 Multiple Channel Help needed

[J-M]

Replace "Read Data Buffer Subset.vi" by "Read Multiple Direct.vi".

"This VI initiates a reading, waits until data is available, and returns that data.  The data is output directly to the bus instead of storing the data in the instruments internal data buffer."

[robert.silva]

Thanks for your support Jean-Marc!

I want to use my Keithley 2750 with a 7703 to obtain a maximum channels/second. In this moment I am using a .vi with a "Read Multiple Direct.vi" (please see the attachment), but I can only read 37 channels / second.

Thats why I want to use the "Read Data Buffer Subset.vi", with this I expected to obtain an improvment.

Many thanks.

[J-M]

I am not familiar with the express vi "Write to Measurement File", but you could separate yours data like this:

It seems for me than you could read about producer - consumer:

https://decibel.ni.com/content/docs/DOC-2431

[Srinivasan648]

Hey friends , 

I have the exact same problem , i am using same program. I have two thermocouples while reading two channels after certain the readings from the channel 2 is transferred to channel 1 and its changing after some period of time. I don't understand what did i do wrong . I am attaching the vi and excel file screenshot . Thank you in advance. 

[JustJohn]

Hello Sinivasan648!

After downloading the VI I was unable to see many of the attached VIs. What was the driver that you used in conjunction with the rest of the code? How are you verifying that the temperature readings are switching over? Do you have one thermocouple very warm and the other very cold? About how long does it take for the values to switch over?

[Srinivasan648]

We are using the device Keithley 2701 and yes i have two different temperatures ( i differentiated one with hot water ). as you can see in the excel file after 147 ( temperature of two thermocouples are swapped)  the reading is switched over. It happens like that and i have attached the zip file where all the basic vi associated with the file are located. Thank you of the help. hoping to get some assitance to resolve this problem. 

[Hey.itsDale]

This is very odd behavior. How often does it occur and what steps do you take to reproduce this?

[Srinivasan648]

Hi Dale ,

Yes ,its very odd for me too. It often occur at some intervals and intervals doesn't seem continous. It's difficult for me to understand why it's happening. It would be helpful if someone can help us resolve this. Thank you 

[Srinivasan648]

Hi Dale ,

Yes ,its very odd for me too. It often occur at some intervals and intervals doesn't seem continous. It's difficult for me to understand why it's happening. It would be helpful if someone can help us resolve this. Thank you 

[Hey.itsDale]

My best guess would be that there is some sort of race condition where the instrument is not processing calls from the instrument driver in the correct sequence.