VISA: (Hex 0xBFFF00A6) The connection for the given session has been lost.

[MarcioCardoso]

Hello,

I am communicating with a TCP/IP device using VISA functions.

If I wait more than aprox. 50 seconds to talk with it, occurs the following errors:

When the VISA timeout is set to 10 sec:

Error -1073807298 occurred at VISA Read.

VISA:  (Hex 0xBFFF003E) Could not perform operation because of I/O error.

When the VISA timeout is set to 20 sec:

Error -1073807194 occurred at VISA Read

VISA:  (Hex 0xBFFF00A6) The connection for the given session has been lost.

When the VISA timeout is set to 20 sec and TCP KeepAlive property is enabled occurs the first error again:

Error -1073807298 occurred at VISA Read.

VISA:  (Hex 0xBFFF003E) Could not perform operation because of I/O error.

Somebody can knows how to solve it?

Regards

[Albert.Geven]

Which device are you communicaing with?

Maybe that information can shed some light, now I have no idea.

[MarcioCardoso]

It is a Telecom product, the manager of a DWDM (optical) system.

[MarcioCardoso]

A workarround is open (write, read) and close the TCP/IP VISA session each time I communicate with it.

What do you think about it?

I usually open and close the device session only one time in my applications, at least GPIB and serial communication...

[JÞB]

I think somethings odd.  Show us some code that demonstrates the behavior and we'll see what's wrong

[MarcioCardoso]

I've discovered the supplier's sw to control this equipment sends packets to it to keep the connection opened. There is no KeepAlive function for it. It has to receive valid packets, a "GetStatus" command for example. If no command is sent, after ~50s, the connection is closed.

[JÞB]

---

@MarcioCardoso wrote:

I've discovered the supplier's sw to control this equipment sends packets to it to keep the connection opened. There is no KeepAlive function for it. It has to receive valid packets, a "GetStatus" command for example. If no command is sent, after ~50s, the connection is closed.

---

If the device is commercially available- could you post a model number and a link to the relavent documentation?  The next forum member that runs accross this issue won't have to share your pain and can resolve a problem with a quick search.  Thanks