Error Hex 0xBFFF0015 timeout problem to read

[IERengg]

I am trying to communicate with a particle counter.  I can write to the instrument but can not read.  I recieve the  Error Hex 0xBFFF0015 timeout problem to read.  The manual for the instrument tells me I need:

9600 Baud rate

8 data bits

1 stop bit

no parity

The output drivers are tri-state with DTR recieve enabled. (I am not sure what this means for my flow control?)

Responds to ASCII command characters.

To communicate I send it an ASCII letter then a carriage return to execute the function.

Recieve buffer is 10 characters long and if overfilled, will ignore all commands except the "space" character which empties the buffer.

All data transmissions are terminated with a <BELL> character (07hex).

I have attached the vi to help with trouble shooting.

Any help is appreciated.

[Wayne.C]

The mention of the DTR line infers some sort of hardware flow control.  Try selecting DTR/DSR flow control and see what happens. 

[IERengg]

centerbolt,

thanks for the suggestion, but that did not solve my problem.  Is there any other suggestions?

[Albert.Geven]

Instead of using the hardware handshaking you can control the dtr line with a propertynode.

make a copy of Bytes at port property
move it after the init serial
change all properties to write
select: serial settings/modem line settings/Dtr state
and use true and false for a test.

I would not CLR the interface because that sends out a break on your serial line and your device can react to that in an unknown way.

good luck

[Wayne.C]

Can you post a link to the manual for the instrument in question?

[IERengg]

I don't believe there is an online copy of the manual.  Sorry.

[Wayne.C]

The ASCII string you are writing starts with a "space" character.  That seems a bit unusual.  I wish I could see the docs for the com protocol, syntax and command set.  Any chance of scanning them to a pdf?   How about the make and model # of instrument?

[IERengg · Accepted solution]

Thanks for everybodys help.  The problem was the clr command at the start of my vi.  I deleted it and the program works perfect.  I love this forum, it is so helpful!

THANK YOU!