Serial Communication with HP33120A Arb. Generator

[Klaus Vestergaard Kragelund]

Hi

I'm using LabWindows 5.01 - so if this is the wrong place to post then I'm
sorry - but I couldn't fint a LabWindows newsgroup.

I've got a HP33120A Signal generator to which I'm communication via RS232.
That works fine hardcoding SCPI commands, but I also downloaded the IVI/VISA
driver. I connot however seem to get this to work - the initialize function
doesn't get through.

this is the first line of my function:

hp33120a_init ("ASRL1::INSTR", VI_TRUE, VI_TRUE, &InstrHndl);

This line doesn't mention baud rate and so on as the one I got from e.g. the
Tektronix TDS220 serial driver.

The documentation for the driver states I need to run Measurement &
Automation eXplorer (MAX) and setup the port manually. This seems s
tupid -
isn't there a way to do this manually with OpenCom and let the VISA driver
refer to this port ? Or do I have to rewrite it myself ?

Thanks

Klaus Kragelund

[Brian_Vibert]

Try going to this link:

http://exchange.ni.com/servlet/ProcessRequest?RHIVEID=101&RPAGEID=8&RFORMNUMBER=1&RHIDETAG=TRUE&UCATEGORY_0=_46&UCATEGORY_S=0

[Jason F.]

All of the National Instruments developed instrument drivers come with their source code when you download and install them and this source is available for editing/use at your own discretion (the source file for this driver is hp33120a.c, just search for it on your computer to open it). So you can either edit the source to change the port settings programmatically or you can use the method described in the instrument driver help where you set up the settings under MAX.

To programmatically set the port settings the instrument driver will use you can edit the hp33120a_IviInit function so that after it obtains a Visa session for the device with the viOpen functoin call, you can call the viSetAttribute function in CVI's Visa library (found under Library >> Visa.
.. >> Resource Template...) to set up several different com port settings.

Jason F.
Applications Engineer
National Instruments
www.ni.com/ask