Agilent 34461A Timeout Initialization Error

[rpm4158]

Hello, 

Im using an Agilent 34461A and connecting to my laptop via USB and using Labview 2018 on a Windows 10 machine. I downloaded the Plug and Play driver and using the example code for single measurement I timeout when I query. In NI max the same result. I downloaded the IVI driver and attempted to use it with my device. Timeout error after initial connection with NI Max and the example code. It is only when I restart the DMM with the USB connected that I can query successfully.  There is a Windows 7 device running Labview 2017 that interfaces perfectly with the PnP driver and runs on initial connection with this device and I have unsuccessfully taken the driver from that computer and try to use it on mine.

I also have access to an Agilent 34405A that I use with a PnP driver on my machine that I have no problems with. I have looked across the forum and tried everything I could find concerning this specific device with no luck. I would ideally want the PnP driver to work but can also use the IVI driver. My USB ports are not turning off and stopping connection with the DMM. Any help would be greatly appreciated. I have attached a file with I/O traces and successful query results. 

Note: I am using NI Visa 18.5 and the most recent PnP and IVI for Labview drivers for the Agilent 34461A

[Carolynn.V]

Hello!

Is your device showing up properly in NI MAX and Windows Device Manager before the device restart?

Have you been able to try a different USB cable or port on the same machine?

[rpm4158]

The Agilent USB address appears immediately after plugging in within NI MAX under the devices tab. I can select it and open the test panel every time. I have tried different ports as well. Previously I had the NI PnP and IVI drivers for the 34461A installed and I could successfully query and measure only with IVI drivers after restart with it plugged in. I installed Keysight IO Library Suite and the Keysight IVI 34461A driver for Matlab and while connected and restarting the device I could measure repeatedly using the PnP driver which is an improvement.

However, if both devices are on and I plug the USB in, in both the Keysight connection app and NI MAX test panels, I timeout when I query *IDN?

It seems like its getting put directly into a fault mode when VISA open is used or something. Im not sure how the device handles unplugging vs restarting concerning connection and opening/read/write from USB port. I appreciate the response as well.

[Carolynn.V]

Does the same behavior occur if the devices are powered off when plugged in initially?

[rpm4158]

Thank you Carolynn for replying,

The behavior, meaning the communication error timeout on querying, occurs only when say my laptop and the DMM are on, and I plug in the USB from the DMM to my computer. If the USB connector is plugged in and I restart either my laptop or the Agilent 34461A I can get a successful query. 

I then went on and tried to further troubleshoot by installing Keysight IOLibSuite 18.1.24130 as my secondary VISA, uninstalling the NI IVI drivers (the installer made me uninstall the NI IVI drivers to install the Keysight one) I had been using and then installing the Keysight IVI and Matlab instrument drivers for the 34461A, I was able to read from the DMM using the original NI Plug and Play drivers AFTER RESTARTING. So, it is somewhat of a solution that I can now use the more convenient PnP drivers but I still had to restart the DMM to communicate with my Windows 10 LV 2018 device. 

I then created an executable for the VI project running on both machines FROM my Windows 10 LV 2018 FOR the Windows 7 LV 2017 machine and after opening the .exe on the older machine the device didnt need a restart to communicate. 

So, on Windows 10 LV 2018 I am still encountering the communication issue. I have attached IO Monitor Logs for both the Failed Query and the Restarted Successful Query. Let me know if there is anything anyone thinks I can try? I appreciate the responses.

[Carolynn.V]

Have you been able to replicate this behavior with different machines with the two OS?