ohaus

[Deboussole]

Hi 

I'm trying to run an Ohaus Discovery balance (DV215CD) with LabVIEW.

I have managed to get the balance to talk to Hyperterminal operating on windows XP via a serial to USB converter attached to the Ohaus provided RS232 cable.

I am running the program 'ohepvp Continuous Measurement.vi' from the downloaded 'ohepvp.llb'.  As the balance is a different model to the one the vi is designed for I have changed the ID query to 'No' on 'ohepvp Initialize.vi'.

The problem is that when I press 'run', the correct mass is shown, but if the mass is changed while the program is running, the vi does not register the change.  If the vi is then stopped and restarted, the new mass is shown, but if the mass is changed again the vi does not register the change again.

Does anybody have a solution or even something I should check so I can provide you with more information to solve this?  As it is working with Hyperterminal I am pretty sure this is a problem with the vi or a setting I need to change.

Thanks for any help you can provide.  I've provided settings below.

Ohaus Balance 

Baud = 9600; Parity = 8, N, 1;  Handshake = Xon/Xoff

Hyperterminal

Configure : Baud = 9600; Data Bits = 8; Parity = None; Stop Bits = 1; Flow Control = Xon/Xoff

ASCII setup : Send line ends with line feeds;  Echo typed characters locally.

COM3

LabVIEW 8.6.1

Baud Rate = 9600; Flow Control = Xon/Xoff   1; Parity = None     0; Data Bits = 8

COM3 

[smercurio_fc]

You need to indicate which driver you downloaded so we can actually see the VI you're talking about. The Instrument Driver Network has 5 pages of drivers for Ohaus.

[Deboussole]

Unfortunately I cannot remember exactly which of the drivers I downloaded.  It is labelled for the Ohaus Explorer/Voyager Pro.  When I checked on the NI website, the vast majority of Ohaus balances had the same download file for the driver.

http://sine.ni.com/apps/utf8/niid_web_display.download_page?p_id_guid=E3B19B3E971E659CE034080020E748...

I have the driver downloaded for LabVIEW 8.0. 

[smercurio_fc]

There's a couple of things you can try:

1. Have the "ohepvp special read" subVI open while you are running the "Continuous Measurement" VI running. The front panel of this subVI shows what it reads from the serial port. Does it show something or nothing?
2. Open and run each of the subVIs used the "Continuous Measurement" VI on their own:
   1. For the "Initialize" VI set the front panel values and then run it.
   2. For the "Select Mode" VI set the front panel values (select the appropriate VISA resource name and Mode) and run it. 
   3. Do the same for the "Configure Units" VI.
   4. Open the "Read Measurement" VI and run it. Change the weight and run the "Read Measurement" VI again. As long as the VISA session isn't closed you can keep doing this.
3. Run the "Continous Measurement" VI in highlight mode. This will help to determine if there's a timing issue.