Any idea on what is causing my serial ports to lock up?

[JPhillips]

I recently purchased the NI serial-usb 4 serial port interface box because I was having a problem of my serial ports locking up, and I thought the problem might be with my serial port card. Well, after a few days with the NI boxes 2 of my serial ports locked up. This is a big problem that I need to get resolved. If anyone has any ideas on what might be causing this please let me know.

I am running Lookout 5.0 (build 7) and Logos 4.4.0.17 on a Dell Windows XP machine with 1GB RAM and a 2 GHz processor. I have already tried recompiling my Lookout file and clearing out my database but the problem still occurs. If I restart the file then the ports start working fine again, but I need to know what is causing this since this
wasn't a problem until about 2 months ago.

Any responses would be greatly appreciated.

Thanks

Jason

[simon]

Probably doesn't help but...

windows probes serial ports for mice etc. With several bits of h/w it
either
1) send crap to the external serial device, and it locks up
2) thinks it found a mouse, pen, edsel, whatever, and installs it,
thus stuffing the port.

There are several fixes for win2k, but they don't work

cheers

http://realterm.sourceforge.net terminal software for real
problems...

JPhillips wrote in message news:<506500000008000000E3890000-1042324653000@exchange.ni.com>...
> I recently purchased the NI serial-usb 4 serial port interface box
> because I was having a problem of my serial ports locking up, and I
> thought the problem might be with my serial port card. Well, after a
> few days with the NI boxes 2 of my serial ports locked up. This is
a
> big problem that I need to get resolved. If anyone has any ideas on
> what might be causing this please let me know.
>
> I am running Lookout 5.0 (build 7) and Logos 4.4.0.17 on a Dell
> Windows XP machine with 1GB RAM and a 2 GHz processor. I have already
> tried recompiling my Lookout file and clearing out my database but the
> problem still occurs. If I restart the file then the ports start
> working fine again, but I need to know what is causing this since this
> wasn't a problem until about 2 months ago.
>
> Any responses would be greatly appreciated.
>
> Thanks
>
> Jason

[Patrick R.]

Hi Jason,

What you may want to try is to create the diagnostics file for each of the COM ports that you are using. That way, you can determine if the serial ports are locking up as data is being sent out of the port or before it is received back from the port. Also, it may show if anything strange is being sent to the port.

This can be done by going into the "Options" menu of Lookout and selecting "Serial Ports". Make sure that you select the proper COM port from the pulldown and check the box in the middle of the dialog screen to enable the Diagnostic File Settings. Provide a file path and file name (such as c:\log.txt) and go ahead and check the two boxes for Timestamp Enable and Value in Hex. If/when the ports lock up, see if you can determine what is h
appening in your Lookout process at the time and then take a look at the log file(s). This may shed some light on the situation.

Hope this helps,

Patrick R.

[JPhillips]

Thanks

I have done what you suggested and will see if that helps me track down the problem. By the way, could a lot of garbled communication cause something like this to happen?

[JPhillips]

Thanks for the response.

[Patrick R.]

It's possible that garbled communication could do this but you would probably get an alarm in Lookout for garbled communication before anything failed to respond. If this is the case though, it may be that the receive gap that is set up for the COM port is not wide enough to accept the response coming back. The receive gap can be increased from the default of 20 to something like 30 or 40, which should be more than enough. Let us know what you find!

Patrick R.

[JPhillips]

I created the diagnostics file and attached is the com port activity that occurred before the com port locked up. I only attached the data from the last minute or so before the port locked up.

Also, I get many garbled communication alarms most of them being "response too short" garbled alarms and my receive gap is set at 100. Is setting the recive gap too high a problem?

Thanks!

[Patrick R.]

Jason,

It should not be a problem to set the receive gap to a 100, although 40 or 50 should be more than enough. It is strange that you are getting so many "response too short" errors. I took a look at the log file and I definately feel that something is going wrong with the communications. I have seen alot of different log files for the communication but I am not familiar with seeing @'s or other special characters as a part of the communication. I also saw apostrophe's and semi-colons, which seem foreign as well. Are you communicating to a device through some sort of converter or something that is part of a network that has to be addressed? Maybe you can try to remove the NI COM ports temporarily and make sure that the comm
unications from the PC COM ports works fine. That way we can narrow down the issue to software or hardware. Thanks in advance.

Patrick R.

[JPhillips]

Our SCADA system uses MDS 9790B Master Radios which communicate with MDS 9710B and MDS 2300 remote radios. At each remote site, the RTU at the site has a specific address so that when Lookout polls that address that site responds. Once the information comes back to the mater radio it goes through a fiber driver and then a modem splitter and then into the NI serial port connected to the master computer.

I will do what you said regarding the PC com port, but before I purchased the NI serial port I was using another four port serial card and having the same problem. However, I had been using that card for over a year and never had the problem until about 2-3 months ago. Therefore, I would be surprised if the NI serial port box
was causing the problem.

Thanks!