Calculation Overflow - MD4 Nuisance System Logs

Luke Ricker 3 years ago in IQANdesign • updated 3 years ago 2

Is there any sort of way to disable "calculation overflow" from making a log in the system log in an IQAN 3, MD4 application?

I know that I should probably make my program not have calculation overflows in math and J1939 output channels in the first place, but when these errors pop up, despite the best programming intentions, and are logged, it worries the customer, who usually thinks something is wrong with the machine.


Satisfaction mark by Luke Ricker 3 years ago

I don't have any way of preventing the system log from logging the calculation overflow when a channel gets this status.

But I think that I can help shed some light on why you are getting this. It appears from the naming in the log as if the channel triggering this is a JPOUT. Attached is a small example that can be used ot cause overflow on a JPOUT:

JPOUT overflow.ids3

I can see that you also have a couple of "unknown" showing Calculation overflow. These must be from channels that you had in the application before, but that were deleted. The IQAN-MD4 does not find the corresponding channel name for the Component ID of the deleted channel, but the stored event is not lost. That is why it reads "unknown".

Thanks Gustav.

That is consistent with what we've found, after some experimentation.

Our workaround is to simply limit the value going into the JPOUT channel.

We set the minimum and maximum limits of the associated function group inputs to 0 and 250, respectively, for all byte values.

This seems to work pretty good.