The first picture shows the Config Wiresheet. The second picture shows the Points
Wiresheet. For the Config Wiresheet, the program commands the Exhaust Fan
with no issue before discovering the Bacnet points.. Upon discovering the Bacnet
points with the "Points Discovery" window and bringing the objects into the Points
wiresheet, the default object will have an OFF and also "Null" for both in10 and in16.
It will then write a Null to the MPX controller's exhaust fan priority 16. It appears that
only priority 16 of this new block does the writing of Null. After this, the script will not
update the Exhaust Fan any further in the Config Wiresheet unless the script toggles
the output in some way to get rid of the "Null" on priority 16.
I could see this being a source of multiple issues if that is the case. I know there is a
Niagara Default Policy to "Write on Start", "Write on Up", and "Write on Enabled"....but
I usually like to keep these on "True".
If priority 16 is Niagara's default, then perhaps it's a good idea for the scripts to write
to priority 9-15 if there is internal logic involved. Just asking a question and possible
issue for the moment.
I am seeing the same issue. If the local logic is writing to priority input 16 the controller should block the external write request. The MNB's function this way. This doesn't solve the issue of how Niagara checks if a point is writeable by writing null to priority 16. If the message is blocked, such as it does with the MNB's, then the point will show a fault in Niagara. We have been programming MNBs to use priority input 15 to avoid both issues and I think MP's should be programmed the same.
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