Measure with Keithley 2000 over RS232

[quixomniac]

Hello

I am also having the same error mentioned above.

As I've read the discussion back and forth, I'll be very detail in what I have done so far.
First off I matched the baud rates, flow controll, terminal character with what is set in the initialize.vi on my keithley 2000.

As seen in the image below

Then I went to NI MAX and made sure these are set in the terminal COM1

Everything checks out until I get to the READ.vi when I get a timeout.

My keithley goes in to REMOTE which means it is communicating but still having issues.

I noticed earlier it was mentioned to make sure terminal char was enabled.

So in NI MAX, I opened the visa panel and got the image below.

I enabled terminal char and made sure to match the type (CR) on my keithley and on visa.

However, when I apply changes and come back to it, it is unsaved. As if I never changed it.

I figure the reason I am getting a timeout error is because the keithley is expecting a termchar,

the software is expecting a termchar, but it isnt being sent because of the port?
this results in a timeout error, because it never gets the termchar.

Any ideas on how to fix this?
Any help is appreciated, I know serial can be tough sometimes.

And believe me, if I could avoid it...I would.

Thanks

(PS. I am using the driver provided by keithley)

[Dennis_Knutson]

What you set or don't set in MAX is irrelevant. The termination character and all other settings are done in the initialize function.

[quixomniac]

Hello Dennis,

Thank you for that bit of information.

I finally fixed it but I don't know why it works. (isn't that always the case with programming?)
I set everything back to default, that is the baud rate to 19200 and flow control to xonxoff.

Same on the Keithley 2000 DMM.

Also, since I was troubleshooting, I closed off everything and turned off all the light bulbs that monitor the VI.

I figured if it was a timeout issue, this would only make things worse.

And voila! It works.

Something in the code with timing is set by default to work with 19200 which I cant seem to find.

I thought simply changing the Initialize VI would work, but it didnt.

Also I got it to work with my serial to USB.

For some who are using this option, make sure to match the settings (baud rates etc.) in the device manager.

It also seems to work with 19200 and flow control none. but not with 9600

[billko]

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@quixomniac wrote:

Hello Dennis,

I finally fixed it but I don't know why it works. (isn't that always the case with programming?)

---

Sincerely hope you were joking because that should almost never happen - although I admit there were a few times I just couldn't explain it.  But those worry me the most because "if it happened once, it will happen again."

In hardware this usually means an intermittent issue; in software it usually means a race condition.

[ratnesh_tiwari]

hello friend,

 I am also getting the same problem... can u help me.???

[mbonux]

I have had some timeout issues using SCPI over RS-232 with the Keithley 2000 (FW13) and I've found a quite simple solution.

I have connected a direct (not null-modem as per the user manual)  cable with *ONLY* RX TX and GND connected (pins 2,3,5 on the DB9 connector) and guess what ?

Now everything works fine, at any baud speed !! Of course  flow control must be disabled.

I would recommend you first give it a try with NI-MAX...

Hope this helps

Michel (FR)