Gpib vs serial performances

[Laurent]

I use an HP34970A acquisition unit with labview via the serial port
(115 Kbauds). I have many measurement that need different
configurations, so I use memorized states of the instrument. I don't
take many points each time, but I change frequently the state.
I think that some messages are not executed:
Would a gpib board speed up the execution ? With witch gain ?
What is the most critical time: communication one or execution one ?
Does anyone has experienced the two communication ways with the same
progam ?

Thank you.


Sent via Deja.com http://www.deja.com/
Before you buy.

[Fabrizio Crestani]

In article <7sfhhb$p02$1@nnrp1.deja.com>, laclau@my-deja.com says...
> I use an HP34970A acquisition unit with labview via the serial port
> (115 Kbauds). I have many measurement that need different
> configurations, so I use memorized states of the instrument. I don't
> take many points each time, but I change frequently the state.
> I think that some messages are not executed:
> Would a gpib board speed up the execution ? With witch gain ?
> What is the most critical time: communication one or execution one ?
> Does anyone has experienced the two communication ways with the same
> progam ?
>
> Thank you.
>
>
> Sent via Deja.com http://www.deja.com/
> Before you buy.
>

Hi, my name's Fabrizio Crestani. (Researcher at university of Triento in
Italy).
I hav
e acquired the data logger, but it doesn't function with LW in
serial RS232 mode.
I have corrected the errors wich concern the files of end string CR
(0x0D) with LF (0x0A). Now, the program runs correctly but it reads
random values.
The native HP-Agilent program of data logger runs correctly by RS232.
My configuration in LW is 115K N,8,1 XON-XOFF.
Could You send me your [initialize.vi] for make a comparison?
I have tested the driver hp and ni, but both don't function.

Thanks.

Fabrizio Crestani

[D.J.Lorier]

I am a mechanical engineering student at the university of Technology
Eindhoven and i am working on a project where a HP34970A and labview is
needed. But the HP34970A acquisition unit with labview via the serial port
doesn't work. I tried several things but it don't work correctly. The
initialize.vi -file doesn't work good, i have got the same problems as
Fabrizio Crestani. Perhaps could you help me?

Thank you,



Dennis Lorier.

"Laurent" wrote in message
news:7sfhhb$p02$1@nnrp1.deja.com...
> I use an HP34970A acquisition unit with labview via the serial port
> (115 Kbauds). I have many measurement that need different
> configurations, so I use memorized states of the instrument. I don't
> take many points each time, but I change frequently the
state.
> I think that some messages are not executed:
> Would a gpib board speed up the execution ? With witch gain ?
> What is the most critical time: communication one or execution one ?
> Does anyone has experienced the two communication ways with the same
> progam ?
>
> Thank you.
>
>
> Sent via Deja.com http://www.deja.com/
> Before you buy.

[Kevin B. Kent]

"D.J.Lorier" wrote:

> But the HP34970A acquisition unit with labview via the serial port
> doesn't work. I tried several things but it don't work correctly. The
> initialize.vi -file doesn't work good, i have got the same problems as
> Fabrizio Crestani. Perhaps could you help me?
>
> Thank you,
>
> Dennis Lorier.
>
> "Laurent" wrote in message
> news:7sfhhb$p02$1@nnrp1.deja.com...
> > I use an HP34970A acquisition unit with labview via the serial port
> > (115 Kbauds). I have many measurement that need different
> > configurations, so I use memorized states of the instrument. I don't
> > take many points each time, but I change frequently the state.
> > I think that some messages are not executed:
> > Would a gpib board speed up the execution ? With witch gain ?
> > What is the most critical time: communication one or execution one ?
> > Does anyone has experienced the two communication ways with the same
> > progam ?
> >
> >

There seems to be several issues here, I will try to take them one by one.
GPIB versus SERIAL
Speed: about 1 Meg BYTE / second - GPIB
about 115 Kilo BITS / second -SERIAL

GPIB is about 80 times faster than serial.

Setup: None really you just need to know the address of the instrument - GPIB
You have to match the settings on the PC serial port and the serial
port of the instrument - SERIAL
Length Limits: 15m max, and no more than 14 devices - GPIB
1200m max(at a lower baud like 9600), one device ONLY -
SERIAL

There are many many more. As you can see GPIB is really preferred for test
equipment.
You can transfer data MUCH faster over GPIB. If you are simply sending a
couple of commands
and then getting some results, it may not make much difference. Usually it
takes more time to execute
a command than it does to send the command to the instrument.
Now on to your problem(s);
Check that the PC serial port and the HP box have the same settings. (The
PC port is set using labview).
In the initialize VI make sure the port settings are correct. Make sure ,if
using VISA, that the correct port number
is supplied. The VI may have been made for GPIB , if so it will need to be
modified for serial.

Kevin Kent