webs ax nci and flash memory

[kempkerr]

On the lon network in AX, if you link to a NCI point will the program write to this point periodically or only on a change in value . The lonworks documentation claims you have to initiate an action "set" comand, but if you link to the NCI object it will update when the value changes. I am very concerned of ruining the flash memory in the controllers if the program continually writes to it.

[amigo]

why are you writing to the nci so often?
Use an nvi instead.

[kempkerr]

Thats the thing I am not, I have some logic that is linked to this nci. About twice a year the value will change. Is this the only time the nci will update or will it update continuosly becouse I have something linked to the object.

[amigo]

I don't know what model and whose controller you are using. But almost all good designs of a controller has/should have safeguards in there from the manufacturer that just because you poll or update an nci value does not/should not mean a write to flash.
A write should only happen if the change is valid and requires a write.

For example if the updates are for the same value to the nci then the controllers' designer should not be writing it over and over to the flash.

Best would be to double check that with the manufacturer of the controller, but I highly doubt they would have not taken that into account somehow.

[checkvalve]

The Ax station should only attempt to write to the NCI on a change in value. It doesn't periodically write to the NCI. If you are using very early 3.0 builds then there was logic to rewrite the NCI if the read and write values didn't match, but in the latest 3.0 maintenance build that has been disabled.

The tuning policy's maxWriteTime does not apply to NCIs. Check the docLonworks out it explains all of that in great detail.