Serial Port Communication Help (RS-232)

[v_pat]

Hi everyone,

    I'm using LabVIEW 6.0 to communicate via serial port to a micro balance at my lab.  I keep getting this error when running the VI.

Status Code: 1073676294

Source: VISA Read in SartoriusTimeMeasure01.vi

Explanation:

Warning 1073676294 occurred at VISA Read in SartoriusTimeMeasure01.vi.

Possible reasons:

VISA:  (Hex 0x3FFF0006) The number of bytes transferred is equal to the input count.

I'm currently using software handshake and i get some data in the Read String output, but it looks like this:

(under read string): \00\00\00

when i use hardware handshake (RTS/CTS) the VI times out every time. Still haven't figure out why.

Any help appreciated..attached is a copy of my VI.  Using LV 6.0

Thanks!

Vishal

[Dennis_Knutson]

You're getting a WARNING and not an error. Otherwise it would be Error -1073676294. This warning can be ignored when you're using VISA Bytes at serial Port to determine how many bytes to read. However, it seems you're also getting incorrect data. On the block diagram, it's written "Print:  ESC P CR LF" but you're not sending the escape character. Try adding a \1B before your P.

[Henrik_Volkers]

The \00\00 you read can be an indicator for not similar port settings.

Another point is the setup of your balance: Sartorius balances have a lot of filter and data output settings that influence your measurement task. Grab the manual, and if you  are in doubt ask Sartorius (or in this treat).  

[v_pat]

Well I put the escape character in, that seemed to solve the hardware handshake problem.  (RTS/CTS) no longer times out every time.

Still getting junk for the output though.  Gonna search through the manual or ask Sartorius for some help.

Thanks

[maple72]

HI all

I have an application to do and I am a very new person in LabVIEW , but I love it it is a very interactive program ,,

my computer  connects  a SA HP8569B  via a GPIB and a microcontoller via a wireless link from the serial port , I want to do the follwing using Labview , check the status of the serial port where my microcontroller is conected to , when there is a a new status in the serial port , I want the HP8569B to make a measurment and record the peak value and then afterwards I want to send a signal to the serial port again hope I am clear and thnaks alot

[Henrik_Volkers]

Does it run with hyperterminal ?

(At these moments I use my RS232 testing vi. it's  postet here http://forums.ni.com/ni/board/message?board.id=140&message.id=11526#M11526 )

Have you checked all serial settings ?  (Parity and No. of bits ?)

[Andy F.]

maple72,

Have you checked out http://www.ni.com/idnet ?  This is a good place to look for drivers for various instruments.  I was not able to find the HP 8569B though.  Could that be the 8566B?  In any case, if you did not have the plug and play drivers, you would have to know how to make a peak measurement.  As for the communication using the serial port, I would recommend looking at the shipping example called "Basic Serial Write and Read.vi" to get an idea how to program using the serial port.  To determine when something is connected you could write to that port and just use the error to determine if the controller has responded.  If you receive a timeout error, then you clear the buffer and write again, or you could keep writing until you receive bytes at port. 

Hope this helps!

Andy F.

[v_pat]

well i finally got the VI to return something other than zeros now, but it is just returning the write command that i send to the machine.

write command is as follows:

\1BP\r\n

escape  P  carriage return  line feed

I dont think its the cabling I followed it exactly from the sartorius balance manual

any ideas?

thanks,

Vishal

[Dennis_Knutson]

It's too bad you're not using LabVIEW 7 or greater. There is a 7.0 instrument driver available. I downloaded it and tried to convert to 6.0 but the driver uses features not available in 6.0. Some of the VIs did translate without problems so you might want to look at them. The ones called Sartorius get Weight with Units and Sartorius Print (this returns a weight as well) are mostly intact.

[VBTECH]

hI,

WE ARE GETTING THE SAME ERROR WHILE COMMUNICATING TEMPERATURE SCANNER. BUT COMES ONCE IN A WHILE. AT THAT TIME WE ARE GETTING WRONG VALUE FROM INSTRUMENT. MOSTLY ZERO. CAN SOME ONE HELP OUT IN THIS REGARDS?