34461A Min-Max Not available like the 34401A

[Foreshadow20]

Hello,

The 34401A is not longer available in Canada. We need to change and use the 34461A as a replacement and we are having trouble with the peak-to-peak measurements (We are using LabVIEW).

We use the peak-to-peak option while reading a communication line in order to get the min and max values. The code:

Visa Write

34410A
CONF:VOLT:AC
VOLT:AC:PEAK:STAT ON
INIT
FETC?

Visa Read

Visa Write

FETC:VOLT:AC:PTP?

Visa Read

This code no longer works with the 34461A. Reading the AC will only give the RMS values. We dont really care how to get the min-max of the communication channel, as long as it is in a respectable time (10s at most...). Reading the signal with DC pretty much stays around the 0V. The communication signal is ±100mv. We verify the min-max range to be around 200mV.

Thanks

[Dennis_Knutson]

If the measurement function is not present in the meter, then you can acquire an array of values and measure the min/max in software.

[Foreshadow20]

The problem is that the array of values are all around 0mV when reading the signal with DC. Either single values in a loop or using the Read Multiple points. Which works fine on AC or frequency reads. But the AC reads are always RMS. I want real values, similar to the acquisition with a DAQ. Or just the highest/lowest value over a period of time.

[Dennis_Knutson]

So instead of rms, you want the unscaled values? Sorry, that's a question for the manual or Keysight.

[mkossmann]

There is an application note on the keysight site about the differences between the 34401A and the 34461A.

One point  says that "the 34641A also suppports overlapped command processing between INIT and measurement completion"

It looks for me that your code depends on the 34401A  non overlapped  command processing and you have to add some syncronisation with  *WAI or *OPC? there.

[mkossmann]

There is an application note on the keysight site about the differences between the 34401A and the 34461A.

One point  says that "the 34641A also suppports overlapped command processing between INIT and measurement completion"

It looks for me that your code depends on the 34401A  non overlapped  command processing and you have to add some syncronisation with  *WAI or *OPC? there.

[Foreshadow20]

if that was the only problem 😛

Many SCPI lines are now giving "Undefined Header" when copy pasted from the Truevolt-DMM-Operating-and-Service-Guide-ENG-2015-2

[Dennis_Knutson]

That does mean much. You haven't said what you copying or what you are pasting to.

[Foreshadow20]

These are a few commands which I noted that always give undefined header:

VOLT:DC:SEC "PTP"

VOLT:AC:PEAK:STAT ON

and others I haven't noted.

Those commands aren't the only lines that I write through VISA. I send other strings before and its at that moment that I get the undefined header error. This includes trying with *WAI and *OSC

Example form the guide:

[SENSe:]DATA2:CLEar[:IMMediate]

Clears the latest result(s) of the secondary measurement. This is typically used to clear the accumulated history of the peak-to-peak function ([SENSe:]VOLT:[DC:]SECondary "PTPeak" or [SENSe:]CURRent:[DC:]SECondary "PTPeak").





Parameter

Typical Return


(none) See example below 

Configure DC voltage measurements using the 10 V range with 1 mV resolution. Select peak-to-peak as the secondary measurement. Make and retrieve measurements. 

CONF:VOLT:DC 10,0.001
VOLT:DC:SEC "PTP"
READ?;DATA2?

Typical Response: -1.84694879E-03;-2.23115575E-03,+5.98403324E-04,+2.82955909E-03 (Data returned in this order: DCV reading, Min Peak, Max Peak, Peak-to-Peak)

Later, clear peak-to-peak secondary measurement data. Make and retrieve measurements. 

DATA2:CLE
READ?;DATA2?

Typical Response: +1.29177114E-03;+6.07221096E-04,+3.43677658E-03,+2.82955548E-03 (Data returned in this order: DCV reading, Min Peak, Max Peak, Peak-to-Peak)
 

CONF:VOLT:DC 10,0.001 (this works)

VOLT:DC:SEC "PTP" (undefined header)