Which points in a station write to the 75F cloud?
Points can be written to in the 75F cloud if they have a writable tag. Points that have this tag on the 75F side will be discovered into the station as writable points (BooleanWritable, EnumWritable, or NumericWritable).
Writable points have 17 input slots (In1 to Fallback). The highest-priority value -- the one you'd normally expect to be written to the point's Out slot -- will be written to the 75F cloud. This value is what appears in the proxy extension's Write Value slot:
Wait. In the picture above, the Out slot doesn't match the highest-priority In slot. That's not how a generic Niagara point works. What's up with that?
Proxy points are different than vanilla writable points. The Out slot follows the latest value that is read back from the device, not the input priority array. This is the Read Value slot on the proxy extension.
In our case, that means that the Out slot contains whatever value was read from the cloud a minute ago. That value will eventually match the value that just got written. But, there are a few steps to this process:
- Point is written from the station to the cloud based on the In value
- Value is updated in the cloud
- At the next polling interval, the point reads the updated value from the cloud, then the Out value is updated.
This means that the Out value of the point lags the In value by a minute or two. A couple minutes later, the Read Value has caught up:
How often do points write to the cloud?
Points write to the cloud on change-of-value, subject to a minimum and maximum time between writes. The default minimum interval is 1 minute, and the default maximum interval is 15 minutes.
How do I change those defaults?
Under the 75F Network, go to "Tuning Policy", then "Default Policy":
Min Write Time is the minimum write interval. Max Write Time is the maximum write interval.
Are there priority levels for 75F points, like BACnet and Niagara points?
Yes! They're explained here.
All writes from the API happen at Level 7. This level is higher-priority than user overrides from the 75F cloud. So, if a setpoint or tuner is set from a station, the user will not be able to override from Facilisight.
Okay, so I can write to 75F setpoints from a JACE. That's cool, I guess. But is there a way to bring non-75F points into Facilisight through the driver?
Yes! But you have to build the points in the 75F cloud first. The tool for creating custom 75F points is called Site Manager (start here).
Then, once the points have been created, you can discover them into the station and write to them.