Controlling old dye laser via ieee 488 with labview 7

[Christoph Bollig]

Hi everyone,

I am cross-posting this in a few groups, because this seems to be a
problem relevant to a number of areas and we are quite desperate to
solve it. Thanks for your time.

One of our students is programming an automated data acquisition
system with labview and has a problem to set up communication to an
old dye laser. It worked with the old measurement pc, an old gpib card
and a very old version of hp-vee, but in labview with the new pc and
gpib interface he just cannot get it going.

The laser is a Lambda Physik Dye Laser FL 3001/2 made in April 1987.
The GPIB "card" is an Agilent 82357A USB/GPIB interface for Windows.

The problem is to get communication between the old dye laser's ieee
488 interface
and a new usb gpib ieee 488.2 interface. He is using
Labview 7 and VISA to control it. But he can only send a byte to the
laser, it switches in remote control and is waiting for the rest, but
there is also no response from the laser to the computer interface.

In theory, the 488.2 should be downwards compatible, but maybe there
are some issues. Or their might be some settings in labview, which we
don't know of.

Maybe someone can help us, or has even got a little program written in
labview, which might help to solve the problem??

Many thanks for your help,

Christoph

[gagir]

I encoutered some old Thermotron chambers with IEE488 that would not
respond properly with the more recent drivers. I think we had to install
NIDAQ 6.0 to fix it. I am not sure it was a problem with the instrument or
if it was just the software that was bad.

Eric Girard


"Christoph Bollig" wrote in message
news:p9u9pv4cm5cv16hdc97cr04japeboobkul@4ax.com...
> Hi everyone,
>
> I am cross-posting this in a few groups, because this seems to be a
> problem relevant to a number of areas and we are quite desperate to
> solve it. Thanks for your time.
>
> One of our students is programming an automated data acquisition
> system with labview and has a problem to set up communication to an
> old dye laser. It worked with the old measurement pc, an old gpi
b card
> and a very old version of hp-vee, but in labview with the new pc and
> gpib interface he just cannot get it going.
>
> The laser is a Lambda Physik Dye Laser FL 3001/2 made in April 1987.
> The GPIB "card" is an Agilent 82357A USB/GPIB interface for Windows.
>
> The problem is to get communication between the old dye laser's ieee
> 488 interface and a new usb gpib ieee 488.2 interface. He is using
> Labview 7 and VISA to control it. But he can only send a byte to the
> laser, it switches in remote control and is waiting for the rest, but
> there is also no response from the laser to the computer interface.
>
> In theory, the 488.2 should be downwards compatible, but maybe there
> are some issues. Or their might be some settings in labview, which we
> don't know of.
>
> Maybe someone can help us, or has even got a little program written in
> labview, which might help to solve the problem??
>
> Many thanks for your help,
>
> Christoph
>
>

[Brian_Beal]

One possible problem is that older GPIB instruments will tell the GPIB controller that they are ready to receive more commands, when they really aren't. I've seen this when upgrading to newer/faster computers. The easiest solution is to put a delay between each read and write command. You could create "new" gpib read and gpib write sub-vi's that have a wait before or after the regular reads and writes. A few milliseconds is usually enough.

You could turn on NI Spy to see if that is the problem. NI Spy slows down the comms, so the problem may not show up when it is monitoring. You should also make sure that the settings for the GPIB controller are correct for the laser, and that the bus timing is set as slow as it can go.

[Ray K]

Older instruments typically do not use EOI and require a termination character for messages. A common mistake in LabVIEW is to send a message with the two characters "\" and "n" instead of sending a linefeed. To append a termination character such as a linefeed to a message you can
a)right click on the string control and select "\ codes display", then type \n at the end of your message
or
b) concatenate a your message and a string constant

[Tony Williams]

In article ,
Christoph Bollig wrote:

> The problem is to get communication between the old dye laser's
> ieee 488 interface and a new usb gpib ieee 488.2 interface. He is
> using Labview 7 and VISA to control it. But he can only send a
> byte to the laser, it switches in remote control and is waiting
> for the rest, but there is also no response from the laser to the
> computer interface.

> In theory, the 488.2 should be downwards compatible, but maybe
> there are some issues. Or their might be some settings in
> labview, which we don't know of.

I don't know the hardware or software you are using, but
your description sounds like you may not have set up the
agreed protocols (between the
controller and the instrument)
that define the End_Of_String..... whether EOS is done in
hardware or software and (if in software) whether the EOS
is defined as a CR or CR+LF.

You have to look in the manual of the instrument to see what
it requires (and/or whether it can be set), and then set the
required EOS in the Labview software.

If you have multiple instruments on the bus, then you may
have to do an individual EOS method for each one.

If you still have access to it, a read of the old programme
that did work may give some hints.

--
Tony Williams. Change "nospam" to "ledelec" to email.

[Eugen T]

Hi Christoph,

We are doing similar things down at our university. Similar (same?) problems
occur when we tried to use 488.2 GPIB interface cards with "old" controllers
that had 488.1 interface. For some reasons those 488.2 did not want to
communicate with 488.1 devices. Anyway, try getting one of those older ISA
488.1 cards or if you want to go the hard way (the way I am connected to one
of my controllers now), use serial RS-232C port - that port in fact is
Universal 🙂

HTH.

viperz (at) mail (dot) com



"Christoph Bollig" wrote in message
news:p9u9pv4cm5cv16hdc97cr04japeboobkul@4ax.com...
> Hi everyone,
>
> I am cross-posting this in a few groups, because this seems to be a
> problem relevant to a number of areas and we are quite desperate to

> solve it. Thanks for your time.
>
> One of our students is programming an automated data acquisition
> system with labview and has a problem to set up communication to an
> old dye laser. It worked with the old measurement pc, an old gpib card
> and a very old version of hp-vee, but in labview with the new pc and
> gpib interface he just cannot get it going.
>
> The laser is a Lambda Physik Dye Laser FL 3001/2 made in April 1987.
> The GPIB "card" is an Agilent 82357A USB/GPIB interface for Windows.
>
> The problem is to get communication between the old dye laser's ieee
> 488 interface and a new usb gpib ieee 488.2 interface. He is using
> Labview 7 and VISA to control it. But he can only send a byte to the
> laser, it switches in remote control and is waiting for the rest, but
> there is also no response from the laser to the computer interface.
>
> In theory, the 488.2 should be downwards compatible, but maybe there
> are some issues. Or their might be some settings in labview, w
hich we
> don't know of.
>
> Maybe someone can help us, or has even got a little program written in
> labview, which might help to solve the problem??
>
> Many thanks for your help,
>
> Christoph
>
>

[Mantra]

"Eugen T" wrote in message news:...
> Hi Christoph,
>
> We are doing similar things down at our university. Similar (same?) problems
> occur when we tried to use 488.2 GPIB interface cards with "old" controllers
> that had 488.1 interface. For some reasons those 488.2 did not want to
> communicate with 488.1 devices. Anyway, try getting one of those older ISA
> 488.1 cards or if you want to go the hard way (the way I am connected to one
> of my controllers now), use serial RS-232C port - that port in fact is
> Universal 🙂

The only difference between 488.1 and 488.2 is that 488.1 defines the
hardware and electrical specs, and 488.2 requires the instrument
respond to a handfull of standard
commands (*RST, *IDN?, etc.) *and*
implement the entire 488.1 spec.

There is absolutely no difference in the GPIB card between 488.1 or
488.2 operation. The likely difference is that you aren't
willing/able to get down-and-dirty with GPIB - most LabView and Vee
drivers I've looked at lately are *hardwired* to *presume* 488.2
commandset availability. This is mostly laziness on the part of the
software developers.

What you will need to do is use the lower-level VISA drivers available
on both NI and Agilent GPIB interfaces. The general programming
involves something like:

viOpenDefaultRM(rsrcMgr);
viOpen(rsrcMgr, "GPIB::16::INSTR", instrHandle);
viPrintf(instrHandle, "*RST");
viQueryf(instrHandle, "*IDN?", buffer);
viScanf(instrHandle, buffer);
viClose(instrHandle);
viClose(rsrcMgr);



MM

status =