Serial Read Error

[te_surrey]

Hi LABVIEW community,

New to LABVIEW but I would really appreciate any advice on the following issue.

The multimeter instrument is connected via a RS232-USB adaptor cable. I am running the example VI Continuous Serial Write and Read.vi and encounter the following error;

Error - 1073807298 occured at VISA Read in Continuous Serial Write and Read.vi

Possible reason(s):

VISA (He 0xBFFF003E) Could not perform operation because of I/O error.

The instrument appears to respond to the write command without issue but the read error occurs in both the example VI and NI MAX.

Thanks for your time.

[Gregory]

The first step is to get your instrument talking in NI MAX. Can you locate it in MAX and open up a test panel? What is the instrument model? Do you have a set of commands for it? 

Most instruments will respond to "*IDN?" and return the model, which is a good place to start.

[RavensFan]

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@Gregory wrote:

Most instruments will respond to "*IDN?" and return the model, which is a good place to start.

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Do they really?  Mind you, I don't mess with out of the box instruments like HP/Agilent stuff as much as I do with simpler serial devices, but I have never worked with something that responded to IDN?.   And looking at the large number of questions that come up in the forums where people have problems with timeout errors, and their code is just using the default "IDN?" command that shows up in the serial examples, or in MAX, I really feel that devices responding to "IDN?" is rather uncommon.

[crossrulz]

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@RavensFan wrote: I really feel that devices responding to "IDN?" is rather uncommon.

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"*IDN?" is one of the main commands in the SCPI standard.  So if an instrument claims to have a SCPI command set, it will respond to "*IDN?".  Granted, most instruments that I have used that use SCPI are connected via GPIB or Ethernet.  There are very few that use RS-232/422.

[Viper]

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@crossrulz wrote:

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@RavensFan wrote: I really feel that devices responding to "IDN?" is rather uncommon.

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"*IDN?" is one of the main commands in the SCPI standard.  So if an instrument claims to have a SCPI command set, it will respond to "*IDN?".  Granted, most instruments that I have used that use SCPI are connected via GPIB or Ethernet.  There are very few that use RS-232/422.

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If it is SCPI compliant. Many serial devices are not compliant. I interfaces with a GPS that didn't recognize the IDN? command . You had to use IDN?* for it to respond.

The original poster needs to tell us the maker and model number of the device.

[crossrulz]

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@Viper wrote:

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@crossrulz wrote:

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@RavensFan wrote: I really feel that devices responding to "IDN?" is rather uncommon.

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"*IDN?" is one of the main commands in the SCPI standard.  So if an instrument claims to have a SCPI command set, it will respond to "*IDN?".  Granted, most instruments that I have used that use SCPI are connected via GPIB or Ethernet.  There are very few that use RS-232/422.

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If it is SCPI compliant. Many serial devices are not compliant.

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I thought I made that point clear.  I was mostly just trying to get the point across about where the *IDN? came from.  But, yes, I only know of 2 instruments I have interacted with that use SCPI over RS-232/422 (Keithley DMM and a NI/TDK power supply)

[te_surrey]

Thank you everyone for responding in such numbers and so quickly. I am working with a TTI model 1906 computing multimeter. Unfortunately this particular multimeter does not have a GPIB port and so I am limited to the RS232 connection.

I have attached the manual for the instrument and my naïve reading is that the *IND? is a legitimate query. Just to confirm I can write to the instrument in both NI Max and using the example VI but run in trouble when attempting to read (or query in NI Max).

Thanks again for taking the time to help.

[Gregory]

How do you know you have no trouble writing to it? Because you don't get an error? Or do you see the instrument responding to your commands somehow? 

Have you made sure that your serial port settings in MAX match the instrument?

[Frozen]

Sounds like there is instrument configuration required too.

From Page 5 of the manual:

"Baud rates 300, 1200 or 9600. Complies fully with the ARC (Addressable RS232 Chain) interface standard. Address selectable from the front panel"

I am not familiar with ARC. Hopefully their is no special cabling required.

[Gregory]

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@RavensFan wrote:

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@Gregory wrote:

Most instruments will respond to "*IDN?" and return the model, which is a good place to start.

---

Do they really?  Mind you, I don't mess with out of the box instruments like HP/Agilent stuff as much as I do with simpler serial devices, but I have never worked with something that responded to IDN?.   And looking at the large number of questions that come up in the forums where people have problems with timeout errors, and their code is just using the default "IDN?" command that shows up in the serial examples, or in MAX, I really feel that devices responding to "IDN?" is rather uncommon.

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Oops, for some reason I was picturing a GPIB device in my head. Now that I think of it, I'm not sure I've used any serial devices that support it, but I have used a few USB devices that support it. As others have said, it will support it if it uses SCPI commands, but it was really just a stab in the dark.