Reading values from Hart Scientific 1529 in Labview

[JenLoong]

Hi,

I am currently working on a project which requires the Hart Scientific 1529 CHUB E-4 to be linked up with the labview program.

As there are no available drivers, I have problems integrating the two components together.

Basically, im just looking at extracting the Temperature/Resistance value from the component so that it can be read in the VI front panel.

Would greatly appreciate any help and guidance. It would be good if anyone shares his/her VI with me.

Thanks..

[Robert-Michael-Ward]

Dear Jen,

How is your instrument connected to your PC?  If it is GPIB/Serial/Ethernet/USB then you will have to use the NI VISA drivers and construct your own instrument drivers specific to your "Hart Scientific 1529 CHUB E-4".

Did the manufacturers provide you with a manual with a series of string commands you can pass to the instrument?  If so then you can test some of these commands through MAX and then code up your own sub-vis in LabVIEW.

Kind Regards,

[JenLoong]

Dear Robert,

The manufacturer had provided me with some basic commands. However, when i tried it out in the NI Max, some of the commands (example, READ? 1) would prompt an error of "VISA:  (Hex 0xBFFF0015) Timeout expired before operation completed." I had tried to increase the timeout timing to 10 seconds but the results are still the same. 

And there is another part where i tried to input *IDN? as the command, it does not respond. However, when i selected *IDN?\n, it gave me a correct feedback. So, i would actually like to check if is there any default suffix that i have to add to the string of commands?

Thanks,

Regards,

Jen L.

[Dennis_Knutson]

The suffix is more typically called a termination character and the default should be explained in the manual. The \n you entered is the slash code for line feed. Another common one is\r for carriage return. You are evidently using a serial connection.

[Dennis_Knutson]

I would suggest you look at the existing drivers for Hart instruments and see if one is similar to your model.

[JenLoong]

Hi,

I have tried to follow some of the instrument drivers, where they will have the basic layout of Visa Write and Read. However, i would always encounter the samae error at Visa Read, where it states timeout of the instruments. However, when i tried the same command in the NI Max, it gives me the values that i wanted. 

Appreciate much if you can assist me on this. Thanks!!

Regards,

Jen

[Dennis_Knutson]

I'm using my phone so I can't look at the VI but did you right click on the string constant and select \ Codes Display? You might also include a screen shot from MAX.

[RavensFan]

I looked at the VI, and Dennis has called it right on.

Your constant is set for normal display, so the \r is two separate characteres a backslash and an "r".  You need to change the constant to \display and edit it.  Then a \r will mean a carriage retrun.

[JenLoong]

Thanks Ravens and Dennis for the help just now, I hope i interpretated your instructions the right way.. But luckily, I managed to display the values from the instrument into labview sucessfully.

However, I have another problem where I face issues with missing data when I attempt to read 4 sets of values. There will be some cases where the values from channel 4 will go to channel 3, where the supposed result in channel 3 just goes missing. I have attached the VI, will appreciate much if anyone can help troubleshoot the problem. Thanks.

Regards,

Jen L.

[Dennis_Knutson]

You still haven't changed the string display. You are still sending the literal "\" and "s". It is a simple right click operation.

You are not configuring the serial port, which is a mistake. The default is to end a read on a termination character which is what you want to use. You are using the Bytes at Serial Port with no wait and that is wrong. Just set the number of bytes to read to some high number and LabVIEW should read just fine.