Other serial VIs available?

[Mads]

Currently we are using the old serial VIs. LabVIEW 6.1 encourages use of VISA, but due to the fact that that requires a separate driver installation (making the process less intuitive, professional and the install sets much bigger...) and requires a licence for each PC it is to be installed on we refuse to use those...(as one can find out a massive number of other LabVIEW users have refused for years, with NI just promising to make things more "seamless").

The old serial VIs work great, however there is one bug that really starts to be a pain. If you use them on ports that are not true serial ports but software emulations of them...which is the case for many types of serial port servers (serial to tcp-ip, Moxa, Advantech, Digi etc. produce s
uch), they (i.e. the write device sub-vi) freeze if the port server is disconnected from the network. That makes them unusable.

Now the question is, has anyone made any serial port VI replacements, based on a dll or other? VIs that we can trust will work even in this case, and can be used even if NI decides to force us all to VISA with no other options...(and still require separate installations and licences)?

[Parks]

"Mads" wrote in message
news:506500000008000000F5760000-1042324653000@exchange.ni.com...
> Currently we are using the old serial VIs. LabVIEW 6.1 encourages use
> of VISA, but due to the fact that that requires a separate driver
> installation (making the process less intuitive, professional and the
> install sets much bigger...) and requires a licence for each PC it is
> to be installed on we refuse to use those...(as one can find out a
> massive number of other LabVIEW users have refused for years, with NI
> just promising to make things more "seamless").
>
> The old serial VIs work great, however there is one bug that really
> starts to be a pain. If you use them on ports that are not true serial
> ports but software emulations of them...which is the cas
e for many
> types of serial port servers (serial to tcp-ip, Moxa, Advantech, Digi
> etc. produce such), they (i.e. the write device sub-vi) freeze if the
> port server is disconnected from the network. That makes them
> unusable.
>
> Now the question is, has anyone made any serial port VI replacements,
> based on a dll or other? VIs that we can trust will work even in this
> case, and can be used even if NI decides to force us all to VISA with
> no other options...(and still require separate installations and
> licences)?



I didn't realize there is an additional license fee for using VISA on target
computers. The double digit growth at NI must finally be slowing down or
they wouldn't have to be going after serial port users for more $$.

I am using a Serial VIs, serpdrv and a USB converter and don't experience
the problem you mention. If I pull the USB converter cable out of the
computer or even disable the com port, I get Error 37 and no freeze up. Is
it just across a network yo
u have this problem? Could you time out the
Write.VI to get around it?

Or maybe I don't understand the problem....

Join the 'Save Our Serpdrv Foundation' today!

[Dennis_Knutson]

I can't help you with your problem with a replacement for the old serial drivers but are you sure about the license requirements for VISA? The full version has a license agreement but I can't find anything about a license agreement for VISA run-time and that's all you have to distribute.

[Mads]

It's more common when using networked devices yes, but we've seen it on one serial card as well (worked fine with all other serial software).

Sign me up for a membership in the "Save Our Serpdrv Foundation":-)

The VISA license has never been the main reason why we do not use it, the main reason is that we cannot easily include it in the same installation as the rest of the software, and the size of it. However - the following thread implies that licenses are necessary:

http://exchange.ni.com/servlet/ProcessRequest?RHIVEID=101&RPAGEID=135&HOID=506500000008000000A63C0000&UCATEGORY_0=_201_%24_13_&UCATEGORY_S=0&USEARCHCONTEXT_QUESTION_0=VISA+license&USEARCHCONTEXT_QUESTION_S=0

I think NI is going the wrong path when they require licenses not just for VIS
A but for other functionality that you get the impression is, and normally would expect to be, free...like e.g. remote panels in 6.1. Where does it say in the 6.1 commercial text that this really is more of a 1 user demo?

[ummagumma]

what that link says is that if you have hardware you want to use visa on, you already have the license (in essence--none required). i don't think the statement is clear but i do think it says you don't need any extra license.

[Mads]

We do not use any NI hardware...the serial ports in use are seldom from NI.

Serpdrv is 25 kB and can be included in an installation simply by adding it to the same directory as the executable. VISA RunTime Engine is about 7,5 MB and requires to be installed separately, flashing the NI logo etc...(I know it can be set up to run silently but still...). And all the functionality we need is in the old serpdrv, is it so strange that we do not like to be pushed twards VISA...I think not.

[Mads]

To add some details and one solution;

What happens if you use a networked serial port server from e.g. Advantech or Moxa and write to or initialize a port if the server has just been unplugged from the network is that the write device function freezes for 25 seconds (not unlike the default timeout of tcp/ip functions). When wrtie device is frozen all serial VIs are at a halt. It is the latter effect that makes it a serious problem because we normally use serial communication on several ports in parallell...it can be tolerable that the VIs handling the port in question halts, but not that all serial comms stop.

In this case we got help from our Moxa supplier though. The Moxa units has an "alive check time" config parameter that is normally 7 minutes. By disabling thi
s (setting it at 0 minutes) the serial VIs do not halt...Problem solved. It would be great if someone at NI could make the serial VIs able to handle the problem by itself (be more robust...), like other serial software does, but in any case we can now use the products from Moxa.