Communication Issue between Driver and Analytical Balance (Mettler Toledo MS3001S)

[BrittR]

Hi,

I am new to LabView need some help. I am trying to create a LabView VI that can read weight values from an analytical balance. There is no driver for the scale I use (Mettler Toledo MS3001S) but a technician from Mettler Toledo recommended that I use the driver for the XS6001M or XS6001S models because they have the same readability and capacity. For both drivers, I opened and tried to run an example VI called 'Mettler Toledo Balances Weight.vi.' However I keep getting the following errors:

Error -1073807343 occurred at VISA Open in Mettler Toledo Balances.lvlib:Initialize.vi->Mettler Toledo Balances Weight.vi. Possible reason(s): VISA: (Hex 0xBFFF0011) Insufficient location information or the device or resource is not present in the system.

I assume that this is because the balance is connected to a different port than the default ('ASLR1'), so I tried the 'COM3' option and got this error:

Error -1074003951 occurred at an unidentified location. Possible reason(s): MTTx Initialize. The ID Query failed. This may mean that you selected the wrong instrument or your instrument did not respond. You may also be using a model that is not officially supported by this driver. If you are sure that you have selected the correct instrument and it is responding, try disabling the ID Query.

Finally, I tried the 'COM4' option just in case that might work, and got this error:

Error -1073807339 occurred at VISA Read in Mettler Toledo Balances.lvlib:Read.vi->Mettler Toledo Balances.lvlib:Command.vi->Mettler Toledo Balances.lvlib:Initialize.vi->Mettler Toledo Balances Weight.vi. Possible reason(s): VISA: (Hex 0xBFFF0015) Timeout expired before operation completed.

I'm not sure what to do. I think the balance may be incompatible with the driver, since the driver was written for a different model. Any suggestions?  I'd be grateful for any help or advice!

Thanks!

[Bob_Schor]

Start with MAX and the Mettler Manual.  The Manual will tell you how to set the serial interface -- you should probably try to set it up for a data rate of 115200 (fairly fast), 8 data bits, no parity, 1 stop bit.  Plug it in to one of the ports on your PC.  Now start MAX, and look at the Serial Devices.  If you're in luck, one of them will say "Mettler Toledo MS3001S".  If not, open each of the serial ports, make sure they are set the same way as your balance (Baud Rate, parity, data bits, and stop bits).  Once you think you know the port, try sending the Mettler its "Attention" command, then read the input and see if you get the appropriate response.  Once you have the port and have verified that it works, you should be able to simply program the port using VISA calls.  [We've done this with other Mettler balances].

BS

[BrittR]

I am missing a serial cable; however, I have a serial to USB adaptor, so I can connect that to the serial port on the scale and plug the cord into my PC's USB. Will this work?  Or should the connection be serial to serial?

Thanks for your help so far!

[BrittR]

Actually, I just realized that the computer I'm using does not have a serial port. There are only USB's!  So, will serial to USB work?

[K_Joy]

Hi BrittR,

Your serial to USB adapter should work just fine. Serial and USB are very compatible with each other.
It is always possible that you will still have problems using a driver that is not designed for your specific device, but the steps recommended by Bob_Schor may allow you to work around that.

Regards,
Kelsey Johnson
Applications Engineer
National Instruments
http://www.ni.com/support
(866) 275-6964