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Independent 2182A measure and 6221/2182A Delta Mode measure

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abir hossain
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Independent 2182A measure and 6221/2182A Delta Mode measure

Post by abir hossain » May 29th, 2015, 11:51 am

Hello,

I am trying to use 6220/2182A for resistivity measurement and Seebeck coefficient measurement running a single labview program. Intention is to measure the resistivity (delta mode) first, abort delta and then measure the voltage only (will heat the sample and measure Seebeck voltage). I don't want to physically change any hardware connection during experiment. So, my question is how can I use the 2182A to measure the voltage after the resistivity measurement?

Thanks.
Abir

Andrea C
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Re: Independent 2182A measure and 6221/2182A Delta Mode meas

Post by Andrea C » June 1st, 2015, 4:53 am

Abir,

For the combined 6221/2182A delta mode, the computer is connected to the 6221 on GPIB or Ethernet. A trigger link cable and RS-232 cable are used to connect the 2182A to the 6221. The computer sends commands to the 6221. The 6221 sends any necessary commands to the 2182A over the instrument's private RS-232 connection.

For independent usage of the 2182A with these connections, you can make use of the SYST:COMM:SER:SEND and SYST:COMM:SER:ENT? commands to relay SCPI commands through the 6221 and to the 2182A. Check the 6221 reference manual for more information.

However, I advise you to test out the feasibility of having the idle 6221 connected to the sample when trying to measure the Seebeck coefficient. The 6221 can source or sink current and it is possible even with the output turned off that it could affect the outcome. Ideally, you would have a switch with good isolation and could disconnect the 6221 when measuring Seebeck.

Andrea

abir hossain
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Country: United States

Re: Independent 2182A measure and 6221/2182A Delta Mode meas

Post by abir hossain » June 1st, 2015, 11:25 am

Hi Andrea,

Thanks for your reply. I wanted to do something like that, sending command through the 6220 to read the voltage from the 2182A. And yes, I will check the feasibility of having the idle 6220 connected while doing the Seebeck measurements.

But I've faced some problems. When reading the voltage from 2182A, I get some strange characters like the exclamatory sign or a triangle sign. I think I need to use some appropriate wait function between the read and write command! Also the 2182A reports "Error -110" on each measurement. I've attached a front panel snapshot with the character and also attached the VI.

I would appreciate if you let me know the cause for this and any possible solution.

Thank you.

Abir
Attachments
Voltage reading.JPG
Voltage reading.JPG (21.44 KiB) Viewed 26939 times
Command through 6220.vi
(10.69 KiB) Downloaded 1102 times

Dale C
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Re: Independent 2182A measure and 6221/2182A Delta Mode meas

Post by Dale C » June 1st, 2015, 12:08 pm

Just a thought on those "strange" characters.
Check to make sure the RS-232 settings on the 2182A match the com port settings on the computer.
Baud
Flow Control
Terminator

abir hossain
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Country: United States

Re: Independent 2182A measure and 6221/2182A Delta Mode meas

Post by abir hossain » June 1st, 2015, 2:34 pm

Hi Dale,

Thanks for your reply. But the KUSB controller doesn't show up in NI-MAX under devices and instruments or under ports in Device Manager. Though I can see GPIB0::12::INSTR in visa interactive control. And I can use visa read/write in LabVIEW.
So, how do you want me to check those settings?

And why the instrument does not show up in NI-MAX? Is there a way to bring it on NI-MAX?

Thanks,
Abir

Dale C
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Re: Independent 2182A measure and 6221/2182A Delta Mode meas

Post by Dale C » June 2nd, 2015, 6:30 am

I thought you were using RS-232.
It looks to me like you are using a KUSB-488B, which is a USB to GPIB interface.
Is this correct?
If so, when you install the KUSB-488B driver there is a selection for Keithley and one for NI.
Choose NI and you should be all set.
By the way, if you choose Keithley the unit still works. it just does not show up in NI-MAX.
I use one everyday with Labview and many Keithley instruments.

abir hossain
Posts: 5
Joined: May 29th, 2015, 11:31 am
Country: United States

Re: Independent 2182A measure and 6221/2182A Delta Mode meas

Post by abir hossain » June 2nd, 2015, 10:12 am

Hi Dale,

I am using a KUSB-488B, which is a USB to GPIB interface to connect the 6220 to PC. 2182A is connected to the 6220 through trigger link cable and RS-232 cable. Just the way instructed for Delta mode setting.

I installed the KUSB-488B driver which is NI command compatible and it didn't show up in NI-MAX. Today I reinstalled the NI command compatible version, but same result. Everything works, just my instrument doesn't show up in NI-MAX.

Actually this was not the issue. I need independent usage of the 2182A with these connections, tried to use the SYST:COMM:SER:SEND and SYST:COMM:SER:ENT? commands to relay SCPI commands through the 6220 and to the 2182A. But I read few strange characters in the output. I attached the VI and a snapshot in previous post. Can you check the VI? I need to figure out this problem.

Thanks.

abir hossain
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Joined: May 29th, 2015, 11:31 am
Country: United States

Re: Independent 2182A measure and 6221/2182A Delta Mode meas

Post by abir hossain » June 2nd, 2015, 10:32 am

Hi Dale,

Using the Fract/Exp String to Number conversion, the characters were gone. Check the screenshot. Though I don't know yet why they appeared in the first place.
Attachments
Command through 6220.JPG
Command through 6220.JPG (98.04 KiB) Viewed 26921 times

Dale C
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Re: Independent 2182A measure and 6221/2182A Delta Mode meas

Post by Dale C » June 2nd, 2015, 12:33 pm

Glad to hear you are working and without the "strange" characters.

Andrea C
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Re: Independent 2182A measure and 6221/2182A Delta Mode meas

Post by Andrea C » June 3rd, 2015, 2:55 am

Abir,

The strange character as the last character in each returned reading is most likely the terminator character which is used to signal the end of a transmission. Usually VISA Read would strip them off for you, but in this case you are using VISA (GPIB) to talk to the 6221 and then access the private RS-232 connection to the 2182A. So VISA is not directly dealing with the RS-232 exchanges and does not strip off the character for you. Seems like you have found a good way to handle it.

Are you still getting error -110? You have a small syntax error in your "Command through 6220.vi". You can send multiple commands in one write operation, but they need to be separated with a semicolon (:SENS:FUNC 'VOLT'; :SENS:CHAN1; :SENS:VOLT:CHAN1:RANG:AUTO ON; READ?").

Andrea

q6712084
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Re: Independent 2182A measure and 6221/2182A Delta Mode meas

Post by q6712084 » August 11th, 2015, 7:03 pm

Dear all,
Thanks a lot the series discussion.

I also use 6221/2182A Delta Mode to measure voltage.
(I'm trying to give DC, and may give AC & pulse in the future.)
Through the "Command through 6220.vi", I can read the data showing in the 2182A.
However, the first read date always wrong as long as I change DC (the data in front of 2182A is correct.)

I have tried clear buffer, it was not make sense.
When I restart 2182A, it seems to give me a random 1st read data.


Very thanks!
Tsao-Chi

Image
http://1drv.ms/1WgU4jg

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