VI for ASL F100 Digital Thermometer

[jhein]

I have been trying to create a LabVIEW VI for my ASL F100 digital thermometer. It says it uses VISA and SCPI command format. I can connect to the device, but cannot pass commands through (ex. *IDN?) using a custom VI or VISA Interactive Control. There is a note that says an interval of 1 ms to 2 ms should be allowed between transmitted characters, which makes me wonder if this could be the problem.

Has anyone integrated a F100 with LabVIEW, or does anyone have any suggestions? 

[Henrik_Volkers]

 I worked a lot with 'simple' µ-controllers that had the exact same problem (due to 1 byte buffer used). Even worse if there is no handshaking implemented....

If you try hyperterm and type in the command you should be able to communicate due to your build in finger delay  😉  (Each stroke is send directly) 

Try better 5ms than 1ms.

 

Message Edited by Henrik Volkers on 11-04-2008 10:56 AM

Message Edited by Henrik Volkers on 11-04-2008 10:58 AM

[smercurio_fc]

It would be simpler to just use String Subset rather than jumping into and out of arrays.

 

Message Edited by smercurio_fc on 11-04-2008 09:07 AM

[jhein]

Thanks for the help. Unfortunately, after implementing the code, I still receive a VISA timeout error. I have increased the timeout value to as high as 60,000 ms, but still receive a timeout error.

My VI is below. Any further suggestions?

 

 -Jason 

[Dennis_Knutson]

Is this a serial or GPIB connection. That's an important piece of information that you have left out.

I'm going to assume serial and have you first performed a sanity check in Hyperterminal? You should do that first to verify that your com settings (which are missing in the VI), the cable is correct, and you are sending the correct commands.

A timeout error is almost always the result of not sending data correctly.

[jhein]

It is a USB Serial Connection. The device connects with Hyperterminal and every command executes properly. The com settings (bits/s, data bits, stop bits, parity and flow control) match the default values (9600, 8, 1, none and none, respectively). I'm at a complete loss.

[Dennis_Knutson]

But what exactly are you sending? Does the command require a termination character such as a CR or LF? If it does, did you set the front panel string control to '\' Codes Display so that you can send a \r (CR) or \n (LF)?

[jhein]

The device does require a CR termination character. I have used Codes Display to ensure that both a \r and \n were entered, but without success. An example function I'm sending is a basic *IDN? command for identification code or SYSTEM:REMOTE, which puts the instrument in remote USB control mode. The front and back end are attached.

Message Edited by jhein on 11-06-2008 03:16 PM

[Dennis_Knutson]

SYSTEM:REMOTE is not a query and you shouldn't be trying to do a read. Queries end with a '?'.

[timcvb]

I made this .vi to configure and read an IsoTech or ASL F100 thermometer. It supports commands to select the Mode (Local, Remote) and the Units (C, F, K, Ohms). You can also select which channel to read (A, B, A-B) or you can ping it with *IDN. I didn't bother with the data logging functions since I will be using LabView to do that. Note that when you switch between channels it takes an extra 5 seconds for the thermometer to switch and take a reading, otherwise if you stay on the same channel it's almost instantaneous. It seems to work a lot better than the U-LOG data logging software that came with the thermometer for my applications. Tim Van Blarcom