FP loses communication to host without triggering watchdogs

[Lachy]

FP loses communication with host. Problem does not seem to be picked up by watchdogs (which have been tested by removing ethernet cable and found to work correctly). Programme worked fine for 2 months without incident. It may be coincidental but problem appears to happen during the early mornings (4 - 6am) when external temperatures are around 3 degrees C. Simply powering off and on the FP seems to return operation to normal.

[Bill B]

Hello,

Thank you for contacting National Instruments.

What is the model number of the FieldPoint controller?(ie. FP-2000)

Regards,
Bill B
Applications Engineer
National Instruments

[Lachy]

thanks for the reply, the model is FP-2010

[Bill B]

Hello,

There are no known issues with the FP-2010 and low temperature. You should be able to communicate with the module from -25C to 55C. If possible, I recommend that you test the controller in an environment has a constant temperature to try to determine if temperature is the main cause of this issue. It is possible that the module has become damaged internally and now is susceptible to temperature.

The other thing you may want to try doing is reinstalling the real-time software on the FP-2010. This may help alleviate a software error that may be causing this problem. To do this, right-click on the Software folder that appears under your FP-2010 in Measurement and Automation Explorer and click Install Software.

Regards,
Bill B

Applications Engineer
National Instruments

[Lachy]

We have also tried running the program embedded on the fieldpoint, however we had the same problem after several days without incident. Basically the program froze in its current state (in this case filling a reactor basin). Once again switching off and on the fieldpoint controller power supply returned operation to normal.

A couple of messages in this forum have reported a similar problem whereby they attributed it to electromagnetic interference. Subsequently they used EMI suppressor beads to fix the problem. Do you think EMI may be a likely cause of our problem also?

Thanks

[Bill B]

It is possible that EMI is causing this phenomena, however, that would mean that the EMI would only be present at the time at which the FP controller freezes. Is there some source of EMI that becomes energized at the same time the FP controller stops working?

One simple step you can take is to place your FP bank in a metal enclosure that will help shield the FP controller from EMI. You can also implement the use of ferrite suppressor beads, but an enclosure is probably the simplest first step.

Regards,
Bill B