RS-232 Problem

[Rob]

Hello,

Can any one identify this data type for me "OO/OO/OO". I am communicating
with a Fowler/Sylvac Ultra Digit Mark V through an OPTO RS-232 9 pin serial
cable. I can command the instrument but when it comes time to record the
data this is what I get.

I do not know what data type this is or how to convert it to something
useful. Nor am I very familiar with Labview.

Why? I am trying to help a friend at University who does not program and
both of us are using the trial version of Labview 6.0i. For the most part
this driver design seems quite simple except for the data that is coming in.

If anyone could help please let me know. This is the only stumbling block we
have left and the timer on the trial version is running out.

Thank you
Robert Marcil

[Jeremy Braden]

Robert,

I wish that I could help you out, but I don't know what that string is either. Most serial instruments return ascii when queried (they return binary that is interpreted into the ascii equivalient). When returning numbers some instruments will return ascii values like 123. Others will return binary which is then interpreted into ascii by LabVIEW which you then have to write code to convert back into numbers. This involves the cast funtion. The latter method is not as common as the first.

To answer your post directly, your instrument manual is best place to learn what that data type is. You may have to contact the manufacturer. On a long shot, I checked NI's instrument download site and could not find your driver, but you may want to look.
ht
tp://zone.ni.com/idnet97.nsf/browse/


Jeremy

[DaveF 141]

There is a loopbank.VI available in the NI libraries that does a good job of showing how serial I/O works - I found that I had to add a 30 ms wait state at the end of its sequence states for it to actually run continuously. May also be named Loopback_LV4.zip and I don't recall exactly where I found it, probably somewhere under serial or RS232 communications.
Good luck - another newbie!

[Labviewguru]

Null characters. You can probably just ignore them, but it depends on a lotof factors.

You need to know more about the protocol of the instrument than you do about LabVIEW.

[DaveF 141]

It might be worth looking at the Loopback.VI that's in the NI Library - probably under Serial or RS232 (don't recall where I found it). Experimenting with the serial loopback function may show you a lot about how NI handles serial I/O. The VI may be named Loopback_NV4.zip or something similar. It helped me build an application talking to serveral remote analog A/D and D/A boards (ONTRAK) via fiber optic links.
And, I found that I needed to add a 30 ms wait timer at the end of the Loopback.VI sequence to enable it to run in continuous mode.
Good luck!
Dave (also a newbie..)