Tektronix Technical Forums are maintained by community involvement. Feel free to post questions or respond to questions by other members. Should you require a time-sensitive answer, please contact your local Tektronix support center here.

2182A Multiple response messages in GPIB doesn't work

2182 Series Support
Post Reply
tetsushmz
Posts: 20
Joined: January 12th, 2011, 8:51 am
Country: United States

2182A Multiple response messages in GPIB doesn't work

Post by tetsushmz » April 6th, 2012, 6:30 am

Hi,

When I send a "*CLS;:INIT;:FETC?;:STAT:MEAS?;:VOLT:RANG?" chained query to the 2182A for the first time, it only returns the response for the FETC? query. But, if I issue the same chained query again, the 2182A responds with the full three responses separated with a semi-colon. How do I get the correct response every time?

Here's how to repro:
(1) Turn on 2182A.
(2) Send a "*RST".
(3) Send a "INIT:CONT OFF".
(4) Send the "*CLS;:INIT;:FETC?;:STAT:MEAS?;:VOLT:RANG?" chained query.
(5) The 2182A returns a single voltage reading such as "-1.05138677E-01" without the responses for the second and third ones.
(6) Now, send the same chained query again.
(7) At this time, the 2182A beeps and shows ERROR -410 on the front panel briefly, but correctly responds with all three responses such as "-1.18083137E+00;32;1.000000".
(8) After that, the 2182A responds with the correct responses for the same query all the time.

The firmware version is C01 A02. The commands are sent over GPIB.

Thanks,

Dale C
Keithley Applications
Keithley Applications
Posts: 2849
Joined: June 10th, 2010, 6:22 am
Country: United States
Contact:

Re: 2182A Multiple response messages in GPIB doesn't work

Post by Dale C » April 9th, 2012, 5:46 am

The -410 error is query interrupted.
This means before the queried data is completely transferred the unit receives another command.
In this case it is the second query. You have three queries in a row.
The is trying respond but ends ups with -410.
Try doing a query then addressing it to talk to get the data.
Then when all the data is sent another query can be issued.
Hope this helps.

tetsushmz
Posts: 20
Joined: January 12th, 2011, 8:51 am
Country: United States

Re: 2182A Multiple response messages in GPIB doesn't work

Post by tetsushmz » April 18th, 2012, 7:47 am

Dale,

That does not explain why I got the correct responses without any -410 errors at step (8). I know the chained query works. I want to get it working at step (4) without going through the extra steps.

Dale C
Keithley Applications
Keithley Applications
Posts: 2849
Joined: June 10th, 2010, 6:22 am
Country: United States
Contact:

Re: 2182A Multiple response messages in GPIB doesn't work

Post by Dale C » April 18th, 2012, 11:00 am

I have since duplicated the issue.
Looks like a firmware bug. it works on other KI products (e.g. 2700)
So I entered in a problem report(bug report).
Should see some action soon on this.

Dale C
Keithley Applications
Keithley Applications
Posts: 2849
Joined: June 10th, 2010, 6:22 am
Country: United States
Contact:

Re: 2182A Multiple response messages in GPIB doesn't work

Post by Dale C » June 6th, 2012, 8:17 am

If multiple queries are sent, the instrument will return them in order, but once a response is available and the instrument is addressed to talk, it will give a response. The output task is unaware that there may be additional queries that were sent in the same command line. As an example, if a status model query, which can be returned very quickly, is followed by a :read? query, which may be comparatively slow, the status model query will be returned immediately if the instrument is addressed to talk while the measurement for the :read? query is still in progress.

Although the SCPI 1993 standard says that all of the responses should be returned in the same response when multiple queries are sent in the same command line, it appears this was overlooked for 20 years. The instruments do return all queries in one line if enough time has elapsed for all queries to be processed. Changing the behavior of the instruments has a potential to break existing applications and create new problems. This is also the first this has been discovered after being around for so long. Recommend to the customer to send one query per command line, or take steps to ensure the additional responses are returned.

Post Reply

Return to “Nanovoltmeters”

Who is online

Users browsing this forum: No registered users and 2 guests