LabVIEW
Serial: VISA or not?
Carola Celeste wrote:
> What are the differences to implement serial comunication with VISA Serial
> or normal?
In LabVIEW 7 you have no real choice. Even the traditional Serial VIs go
ultimately through VISA.
> more precision? Less errors?
A common API which works the way I would expect communication to work.
Also an API which allows you to write one single driver for an
instrument which has one or more of the GPIB, RS-232, VXI11 (TCP-IP), or
USBTMC interfaces.
Also an API which is the same on all platforms of LabVIEW, supports more
properties and aspects of the serial port than the traditional VIs ever
could and an API which is not just LabVIEW but can be used from any
programming environment.
Rolf Kalbermatter
> What are the differences to implement serial comunication with VISA Serial
> or normal?
In LabVIEW 7 you have no real choice. Even the traditional Serial VIs go
ultimately through VISA.
> more precision? Less errors?
A common API which works the way I would expect communication to work.
Also an API which allows you to write one single driver for an
instrument which has one or more of the GPIB, RS-232, VXI11 (TCP-IP), or
USBTMC interfaces.
Also an API which is the same on all platforms of LabVIEW, supports more
properties and aspects of the serial port than the traditional VIs ever
could and an API which is not just LabVIEW but can be used from any
programming environment.
Rolf Kalbermatter
Carola Celeste wrote:
> But what is the best way (the faster) to permit LabVIEW to comunicate with a
> microcontroller, by RS-232?
> VISA or VIs?
I'm not sure I understand your question. Fast in terms of development or
in terms of communication? Development would mostly depend of what you
already know. I prefer VIS because I know it quite well. As far as
reaction time to VISA communication is concerned I would say there is no
real difference even nowadays where the Traditional Serial VIs in fact
go through VISA anyhow when you go into the VIs and look deeper.
The only thing which would be really faster is directly programming the
serial port chip on register level through a device driver for the
device you want. But device driver developme
nt is a tricky business and
there is no way to do without C programming, low level system debugging
and such, so I'm quite sure it is not what you are looking for.
Rolf Kalbermatter
> But what is the best way (the faster) to permit LabVIEW to comunicate with a
> microcontroller, by RS-232?
> VISA or VIs?
I'm not sure I understand your question. Fast in terms of development or
in terms of communication? Development would mostly depend of what you
already know. I prefer VIS because I know it quite well. As far as
reaction time to VISA communication is concerned I would say there is no
real difference even nowadays where the Traditional Serial VIs in fact
go through VISA anyhow when you go into the VIs and look deeper.
The only thing which would be really faster is directly programming the
serial port chip on register level through a device driver for the
device you want. But device driver developme
nt is a tricky business and
there is no way to do without C programming, low level system debugging
and such, so I'm quite sure it is not what you are looking for.
Rolf Kalbermatter
