Priorities are used within the SmartServer to determine the current value for a datapoint and when writing to a datapoint. Priority values are normal, and 1 (highest) through 16 (lowest). Each writable datapoint has a priority array. The highest priority determines the current value. You can write to a lower priority and then the current priority, causing the new value to be added to the datapoint priority array. Doing so will not change the current datapoint value since a higher priority setting exists.
Priorities are used by the schedules and allow you to override the current value for a period of time. The priority array allows you to set specific values for each priority. In this way, you can write a value for each of the priorities 1-16, plus normal priority, with the highest priority taking precedence. You can manually relinquish any of the priorities. When you relinquish the highest priority, the next highest configured priority takes precedence.
Datapoints widget View Overrides dialog
A value of null means that a value has not been assigned for that specific priority number.
For example, if you have a light that you want to turn on during the night and off during day, and you also want to allow someone to override the current setting (that is, to keep it on or off), then you could do the following: 1) create an all-day schedule event that turns the light on with normal priority and 2) create another event to turn off the light from sunrise to sunset at priority 16. If someone wants to set the light on or off, then they can use the SmartServer web pages to set the datapoint value to on or off at a higher priority (e.g., 15). In this case, the light will remain in this state until the priority level is relinquished, or someone writes to this datapoint at the same priority or a higher priority (e.g., 10).
The datapoint priority setting is only sent to BACnet devices; it is not sent to LON or Modbus devices. LON and Modbus devices have no concept of priorities. Instead, whatever was written last to the datapoint is the current value. Many BACnet devices support priority levels, although it is not required.
Working with BACnet devices, or using a BACnet tool to access LON and Modbus devices connected to a SmartServer
The SmartServer supports priorities 1-16 and normal. BACnet supports priorities 1-16.
If you use the SmartServer to write to a BACnet device, then the SmartServer will write to the BACnet device using the priority that you specify. Since the SmartServer supports normal priority, which is not supported by BACnet, then when you write at normal priority, the SmartServer will actually send the value at priority 16.
When you use a BACnet tool to write to a LON or Modbus device within the SmartServer, then it will only use priorities 1 through 16. This means that a BACnet tool cannot write to normal priority. If you are using a BACnet tool, then make sure the lowest priority that you use in the SmartServer is priority 16 for schedules and when writing to the LON or Modbus device.