02-05-2022 01:53 PM
Hi all,
I am trying to use LabVIEW to read in Keithley 2000 multimeter voltage values. We tried using the Keithley 2000 manual for setting up RS232 settings, so it seems like the Keithley is ready to go. On Labview, we downloaded from "Find Instruments" the Keithley 2000 Driver which has the examples "ReadMultiple.vi" and "ReadSingle.vi" which we tried to use. We get the error number: 1073807246 (the resource is valid, but VISA cannot access). We also have gotten a "Timeout expired" error, even though Ni MAX and all other LabVIEW windows were shut. On VISA Test panel, we set up with the flow control set to "XonXoff", baud rate 2400, and enable termination character, which to the best of our knowledge matches the Keithley settings. We send the code ":MEAS[:VOLT:[DC]]" on VISA I/0 panel, then close out of NI Max before running Labview as we are under the impression that NI Max will compete for control if left open.
Questions: How can the test panel communicate with LabVIEW when it is not open? When we reopen the test panel, we have to re-enter the settings, even though we had hit "Apply Changes" before quitting test panel.
We've been working on the provided examples, but when making our own program, we had tried using the Instrument I/O Assistant. Is this what should be used?
We don't have much Labview automation experience, so any advice would be greatly appreciated.
02-21-2022 09:00 PM
Any reason you would want to go with RS232 and not GPIB?
The most important thing did you configure the DMM to use the RS232 or remote control? most instruments disable remote control by default.
This article will be helpful to understand the basics to communicate with instruments using LabVIEW
https://labviewwiki.org/wiki/VIWeek_2020/Proper_way_to_communicate_over_serial
02-21-2022 10:09 PM
@santo_13 wrote:
Any reason you would want to go with RS232 and not GPIB?
Unless you already have a GPIB controller, cost is a major factor ($1k for a GPIB controller, $50 for an industrial grade USB-RS232 adapter). I purposely avoid GPIB purely because of this cost. My preference is Ethernet (LXI), followed by serial. I really do not like using USB, but will if being forced to.
@santo_13 wrote:
The most important thing did you configure the DMM to use the RS232 or remote control? most instruments disable remote control by default.
It has been a long time since I have used a Keithley 2000. It was a great DMM. But I will state that most instruments need the remote control port to be configured. And since we are talking RS-232, you need to make sure all the settings are also correct (baud rate, stop bits, etc.). To take it a step further, you also need to make sure the instrument doesn't require a cross-over connection (my current project has one of these).
@santo_13 wrote:
This article will be helpful to understand the basics to communicate with instruments using LabVIEW
https://labviewwiki.org/wiki/VIWeek_2020/Proper_way_to_communicate_over_serial
That presentation is amazing. Whoever did it is a freakin' genius! 😎