Reading Data from 2182A Nanovoltmeter

[vaibhavinegi]

I am using 6221 Current source and 2182A Nanovoltmeter to perform IV Measurement.
Please help me how to read data from 2182A voltmeter in Sweep Mode.
I am using commands:
SYST:COMM:SER:SEND “VOLT:READ?"
SYST:COMM:SER:ENT?

But its not working.
Throwing an error of Invalid Character.

[Dale C]

Just send the :READ?
You do not need the :VOLT
That will cause the error you see.
This should do it.
SYST:COMM:SER:SEND “:READ?"

[vaibhavinegi]

Why 2182A respond string is double exclamation?
I have changed the query to :READ? as you suggested.
Now I am only getting "!!" string instead of Voltage.
I have tried FETCh also and it is also giving the same output.
Even any other query like SENSe:RANGE? also giving the same result, which is "!!"
Please help me.

[Dale C]

I believe you are using RS-232 as the communication bus.
I am not sure of the SYST:COMM:SER:SEND portion of the command.
All you need to send (however you get it to the instrument) is
READ?
The double exclamation points makes me think there is something wrong with the RS-232 parameters.
BAUD
DATA BITS
FLOW CONTROL
TERMINATOR
My guess is flow control in not matched. Whatever the 2182A is set to (XonXoff, NONE) make sure the com port parameters are matched.
Also the same with the terminator. If you use CR then the 2182A and com port should be CR.