Keysight 34972A with 34901A Separate banks

[Kenny_K]

I am using the 34972A with 34901A and I want to use the Bank 1 as a multiplexer for my power supply (opening and closing relays to connect to different points), and then Bank 2 for measuring Voltage across various parts of my UUT.  I know that many LabVIEW users use the same DAQ with the card, so I thought I would ask here too.

The issue I am having is that the bank switch is closing and my bank 2 measurements are off due to the bank switch being closed or I get an error 301: "The channel is part of a scan".

I am aware that in the manual it says "If any channels are configured to be part of the scan list, you cannot close multiple channels; closing one channel will open the previously closed channel. " but i didnt think I had anything configured as part of a scan list.

I copied the actual SCPI commands from the LabVIEW driver VIs.

*RST

;Open bank switch (also tried close, with the same results)

ROUT:OPEN(@199)

;connect to PSU1

ROUT:CLOS(@101)

;close relays to connect to another device, using module in slot 2

ROUT:CLOS(@212)

ROUT:CLOS(@214)

;measure voltage across channel 113

MEAS:VOLT:DC? 1, DEF, (@113)

[RTSLVU]

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@Kenny_K wrote:

I am using the 34972A with 34901A and I want to use the Bank 1 as a multiplexer for my power supply (opening and closing relays to connect to different points), and then Bank 2 for measuring Voltage across various parts of my UUT.  I know that many LabVIEW users use the same DAQ with the card, so I thought I would ask here too.

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I have been using these instruments for over a decade and I do not understand your question.

Can you please explain what you are trying to do.

You say Bank 1 and Bank 2? The 34901A is a multiplexer card, as far as I know there are no "banks". Each channel is configured to take an individual measurement.

It sounds like you need a, 34903A Actuator card for your power supply (opening and closing relays to connect to different points) to use along with the 34901A Multiplexer card to take measurements.

BTW: There is a full featured Plug & Play LabVIEW driver available for the HP/Agilent/Keysite 34970A and 34972A available. No need to mess around with the raw SCPI commands.

[Kenny_K]

I have attached the schematics for each bank, as well as the schematic for the 34901A.  the bank switch is accessed by doing a switch (LabvIEW plug and play vi or ROUT:OPEN or CLOSE in SCPI on channel 199 (if in slot 1)

The 34901A can be divided in to two bank for 2 wire measurements, for combined for 4 wire.  I am only wanting to do 2 wire.

The current sense on the Bank 2 (channels 111-114) are measuring voltage across a shunt resistor (resistor not shown).

Yes, I am using the LabVIEW plug and play drivers, but I figured that the actual SCPI commands would be more helpful, since the SCPI commands are what are references in all the Keysight manuals.

[RTSLVU]

I still don't understand what you want to do with the two banks.

You know the 34901A MUX cards only take measurements right? 

You can not use the relays to route signals like an actuator or switch matrix card. 

[Kenny_K]

You can not use the relays to route signals like an actuator or switch matrix card. 

Sure you can......  Just like I have it wired in the PSU schematic, I have the power supply going into the Source Input, and then I switch between the three battery terminals.  I do not use the DMM in this case, just routing the power supply to the three different locations.   Been using the card like this for 5-7 years in production testers.

here is a except from the Keysigh forum: The 34901A channels provide a path to the internal voltmeter as well as to the COMmon terminals on the 34901A.   It you just want to use the 34901A as a switch to rout signals from the channel terminals to the com terminals, connect your external voltmeter to the com H & L terminals, short the wires connected to the channel terminals together and measure the resistance.  Alternatively just configure the channel for a 2-wire resistance measurement as shown in the manual and use the 34970A to check the continuity.   Look at the 34901A diagram in the manual to see how the signals are routed.  You can find the manual at www.agilent.com/find/34401A.

https://community.keysight.com/thread/18747

[RTSLVU]

Well good luck with that... I am done here.

[TomMc7]

Hi Kenny,

I have a similar application where I needed ten 2 wire measurements and some low current dry contacts.for a test fixture.  I encountered the two issues you saw:

1) error 301.

2) bank relay getting in my way.

For the error 301, I issue a reset, (Agilent 34970 reset.vi) after my scan measurements or before issuing a relay activation command, (Agilent 34970 switch.vi) on the sense bank.  You can use a voltage measurement command to activate the dry relays also, but i like to use the switch command to remind me of the modified card.  I also labeled this 34901 card with the modification to keep others from "acquiring" it LOL!

The modification:

To configure the sense bank for my purposes, I removed the bank relay (K422, next to the 4 common screw terminals) and installed a through hole polyswitch across the 4W common sense screw terminals.  The polyswitch I used is about 15 Ohms under 150mA.

These dry contacts don't operate at the same time with the standard Agilent VIs I'm using, but that is not a problem for my current application.  I could see this as another enhancement for a matrix application.  The hardware logic might be preventing this.  If anyone else has tackled this, please chime in!

I bought a few 34901s online, refurbished for $349, so i don't mind modifying them.

Tom