Controlling the Thermotron 7800 going USB to RS232.

[tburgess]

     I'm very new to LabVIEW so I apologize if this is a quick fix I haven't stumbled across.  My goal is to control my Thermotron 7800 which has an RS232 interface with a machine that only has USB.  I'm using the  manufacturer's LabVIEW drivers with LabVIEW 8.2.1.  I've mass compiled them per instructions so they'll work with my 8.2 as they were written for LabVIEW 7.1.  I've connected and used a 3rd party USB / RS232 converter with other hardware to this machine so I know that's not the issue and I can get the LabVIEW driver to recognize what port I'm connected to but I know no data is transferring across the cable as the indicator LED is not flashing and all I can get is a time out error.

     Anyone tried this before?

[falkpl]

Have you verified communications with the instrument with hyperterminal or similar apps?  Your problem could be in recognizing the USB/232 converter or possibly with the serial settings (BAUD, Parity, start bits .....)

Paul

[Andy L]

Hi,

I have a few questions/suggestions regarding your system. 

1.     When installing the USB to rs232 convertor did you create a driver using the Driver Development Wizard?  The following link will help you create an inf file to ensure proper communication with the instrument. 

http://zone.ni.com/devzone/cda/tut/p/id/4478

2.     Use the following link to try a loopback test to verify the usb-rs232 hardware is operating correctly.

http://digital.ni.com/public.nsf/allkb/E22DA85E97818DE78625678C0069BFC9?OpenDocument

3.     Verify with the Thermotron manual that all the serial settings (BAUD rate, Parity, Start and Termination characters) are correct, like falkpl suggested. 

4.     Try communicating to the instrument using a VISA test panel in Measurement and Automation Explorer.  The VISA test panel can be accessed by right clicking on COM1 from Devices and Interfaces>>Serial & Parallel.  The test panel allows the user to test basic serial write/reads without writing any code.

Regards, 

[tburgess]

Andy,

     Thank you very much.  It turns out I was getting data accross the USB to RS232 fine, my issue was the output pins on the converted were null so I got another null cable to get my #2 and #3 RS232 pins back in line and I'm all set.  Your suggestion for the Basic  i/o test did the trick.

     Also, for future readers, don't get caught into COM 1 as suggested above, my USB ports are COM 5 & 6.

Message Edited by tburgess on 08-30-2007 09:40 AM

[jd83]

Hi

I am using a USB to Serial connection, with a 3 null RS-232 cable.

I have downloaded the drivers and placed the file in the correct location and mass complied as per instructions.

I have also placed the .dll file into the correct file which I created

Next I am trying to send commands through the visa test panel but I am still receiving a time out error

Have you any ideas were I am going wrong.

[Dennis_Knutson]

Duplicate - http://forums.ni.com/t5/LabVIEW/Thermotron-Chamber-controlled-by-Labview/td-p/2348620

Please stick to one thread.