Instrument Descriptors... newbie help

[doug.shade@freescale.com]

Thanks for reading.

Win 2K with PCMCIA GPIB card
Drives E1406A Slot 0 Controller in VXI chassis (GPIB address 9)
Slot 3 has E1411B (logical address 18)

HP's soft panel drives 1411B no problemo... so I know the hardware is all there.

NI's HPE1114B.vi "getting started" can't seem to communicate?!

What should the instrument descriptor be?

GPIB0::9::INSTR ?
GPIB::9::INSTR ?
GPIB0::9::3::INSTR?
GPIB0::9::18::INSTR?

Lost... and I think the descriptor is my problem. Any help getting of top dead center would be appreciated.

Cheers,
Doug

[Dan_Mondrik]

Doug:

The GPIB-VXI controller is a special case. So you really should have a GPIB-VXI controller configured in your software at primary address 9.

But I am guessing that your main problem is that the 1406 requires all VXI logical addresses to be a multiple of 8. So you should set it to either 16 or 24. Then the secondary address is the logical address divided by 8.

(Note that the National Instruments GPIB-VXI controller does not have this same logical address restriction.)

Let's assume you reset the logical address to 24.

The most correct resource descriptor is this:
GPIB-VXI0::24::INSTR

Note that for 488.2 message based instruments, you could also just use the VXI device's secondary GPIB address:
GPIB0::9::3::INSTR

I hope this helps.


Dan Mondrik
Senior Software Engineer
National Instruments

[doug.shade@freescale.com]

Dan - Thanks for the "modulo 8 tip", but still no joy. So... from the top.

VXI crate
SLOT 0 has E1406A GPIB controller, address 9
SLOT 3 has E1411B multimeter, LADDR=0x18 or 24 decimal
SLOT 5 has E1458A dig. I/O, LADDER=0x28 or 40 decimal

Using NI's "hpe1411b_Initialize.vi" I don't seem to be able to communicated with anything : (

Running the VI returns the message:
"Insufficient location information or the requested device or resource is not present in the system."

I get that same error whether I use:
GPIB0::9::3::INSTR
or
GPIB-VXI0::24::INSTR

Using the soft panel provided by Agilent... I can effectively communicate with the multimeter.

Using NI's MAX, I see:
Instrument 0 at GPIB0::9::0::INSTR (E1406A controller)
I
nsturment 1 at GPIB0::9::3::INSTR (E1411B multimeter)
(but no E1458A... dead board?)

AND... can "communicate with instrument"... the IDN command is responded to as expected.

SO... I'm stuck. The hardware is obviously there; MAX and an Agilent soft front panel can converse. But... I can't seem to get any intelligent response from the VI.

Now all that being said... I've been a LabView user for about 4 hours so this is very most likely "rookie pilot error"... but I've messed around and messed around and can't seem to talk to the instrument.

Is there some pre-conditioning step I am missing, i.e. do I need to do something to the Slot 0 controller to open a channel to the VXI crate?

Thanks Very Much. Doug