Newbie having problem communicating with simple serial connections with HH506R

[anupamaich]

Hi All,

I am a newbie with llabview & I was trying to communicate with a HH506R omega thermometer using serial port communication. I tried to use the parameters (such as Parity, baud rate, sto bits) as per the manual. I could write the data from the write string & it responses to it. But while returning the data, it shows a framing error & I am also not getting the read string in therms of ASCII characters. It's just random character which I don't know how to convert to ASCII format. Is there any way to convert the hexadecimal to the ascII characters?

I am using the Basic serial write and read vi from NI.

Regards

Anupam

[EricLarsen]

Sounds like you still have one of the parameters set wrong. The values shown in the manual are probably the default values for the HH506R, it's possible they have been changed. Try different values, starting with BAUD. You might get lucky.

[Dan DeFriese]

From the manual's example code in QBasic.

OPEN "COM1:1200,E,7,1,DS,RS" FOR OUTPUT AS #1

I see that the port settings are

Baud Rate = 1200

Parity = Even

Data Bits = 7

Stop Bits = 1

...and there may be hardware handshaking "DS,RS" (I've never actually used QBasic... just seen it once on the History Channel!)

Are these the settings you're using?

[cchipman]

Serial port problems are usually pretty straightforward to solve.

Check that you have a proper serial port cable, not a null modem cable (the receive and transmit lines are crossed in the cable) between the PC and the device.

If you are on a Windows XP system, use HyperTerm (Start->Accessories->Communications->HyperTerm) otherwise, download TeraTerm (it's free - search on TeraTerm).

Set up HyperTerm to use the proper COM port, and configure the baud rate, stop bits, etc. for your device.

Send a command string for the device and check the response.

If everything works, great. If not, start playing with baud rates and other parameters.

Once you are communicating successfully via HyperTerm, then move to LabVIEW to open and configure the port, then send and receive characters

Good Luck.