rs232 receive file how?

[pam1]

I have trouble receiving a text file from my instrument. It is set up with 9600, 8, 1, none, Xon/Xoff. When I try to receive the file I get nothing when using either Hyperterminal or Measurement and Automation explorer. Part of the problem might be the modem type I'm supposed to select. I've tried all of them and nothing. Can someone help? Pam

[pam1]

Oh, yeh, the return value I get in Measurement and Instrumentation is BFFF0015 in red. My instrument is a flowmeter.
Pam

[Ben]

THat is a time out error.

That is as far as I can go with the info you provided.

More data >>> More ideas.

Ben

[DiegoF]

Hi,

The fact that you are not able to communicate using Hyperterminal means that something at a very low level is not working properly. It is very uncommon for the built-in serial driver to fail, so I would suggest checking the cabling.

If you are conecting to PCs you must use a null modem cable. Since you are not using any hardware handshake you only need to swap pins 2 and 3.

When you refer to modem setting, I assume that you are using Hyperterminal's transfer file functionality. Although I'm not to familiar with the modem settings, I don't think that would cause this. I have made it work just by setting the same modem protocol on both sides.

Hope this helps.

DiegoF
National Instruments
www.ni.com/ask

[pam1]

Hi,
Thanks for the suggestion. I have done this, changed the rx and tx pins. Still I get nothing. Any other suggestions are appreciated.
Pam

[DiegoF]

Hi,

Try to do a loopback test. You can do this just by shorting pins 2 and 3 on the serial cable. This makes the serial port receive whatever it sends.

You can then use HyperTerminal (configured to none handshake to start with). Anythin you type using HyperTerminal should show up on the same terminal.

Other than that I don't know what else to do. try using a different PC.

Hope this helps.
DiegoF
National Instruments.

[pam1]

Thank you for your suggestion.
I am able to 'talk' to other instruments using this pc. Also, I have tried my flowmeter with three pcs and still I am unable to 'talk' to it.

The instruction is this:
Set up the hyperterminal with Xon/Xoff.
Ask the hyperterminal to receive file from the port.
Send the file to the port from the flowmeter.

The hyperterminal receives nothing.

With Xon/Xoff which should come first? The request of the hyperterminal to receive the file or the instruction of the flowmeter to send. With Xon/Xoff does the sending instrument require a flag from the receiveing terminal before it can send? In which case should I send the data then ask the hyperterminal to receive?

Either way, currently I am unable to receiv
e the file.

When I connect the tx pin of the flowmeter to an oscilloscope I see digital data. So the flowmeter is sending something when I ask it. Why then can I not receive it in hyperterminal?

Response appreciated.

Regards,

Pamela

[DiegoF]

Hi,

The Xon/Xoff protocol is handled automatically by the driver. You don't have to worry about sending the Xon/Xoff characters.

I think you need to check the flowmeter's user manuals for any detail you can find on what is the protocol and serial port settings it is using to communicate.

When you see data comming out of the device, but the PC cannot detect the data, it usually means a baud rate problem.

You also mentioned that you were using Hyperterminal's transfer file functionality. Find out exactly which of the protocols the device is using.

Finally, you may also need to contact the device manufacture's tech support. We con only give you general info on the serial port comm, but it seems that you are mi
ssing some device specific setting.

DiegoF
National Instruments