Flow Rules in the NLP

The NLP organizes flow via a network of Hydraulics. Flow Rules are established by individual flow meter as assigned to a Hydraulic Tree under a Rule. Before establishing Flow Rules, consider the Hydraulic set-up that matches your site's needs:

• For basic installations, Hydraulics should be established with 1 mainline, & flow sensor(s) can be added to a single main. The NLP will react to combined flow readings controller-wide. 
• For more complex installations, Hydraulics can be organized into something representative of the actual site via Pipes.
  • The NLP can accommodate up to 20 points of connection, with 20 individual flow meters & flow valves (N/O or N/C master valve, relay, or booster pump). 
  • The NLP supports up to 100 pipe sections. 
  • Flow Rules are set at each Pipe. Flow Rule states, action & type can differ between each rule, allowing for flexibility of complex systems. 

Hydraulic Rules have two states:

• Active: An Active Flow Rule triggers the NLP to refer to rule settings. This is the default setting for Flow Rules. 
• Inactive: An Inactive Rule enables the functionality of a flow sensor & flow valve without using a Rule. Users that want to see real-time flow on the controller dashboard & log flow values without Rules should use this state. Disable a flow Rule by deselecting Active in a respective Rule. 

For a given rule, action can be enabled at two levels:

• Standard action: This action level is largely notice only. Notices are reported, mentioned on the controller dashboard, and sent as a Alert if a user or organization has subscribed. This is the default setting for Flow Rules.
• Automatic action: Standard Action + additional controller functionality. Enable this under a respective Flow Rule by selecting Automatic action. 

Flow Rule Definitions:

• Rules
  • Allowed Idle Flow (GPM) (Unscheduled Flow): Allows for (background) flow unrelated to the controller. E.g. a hose bibb or quick coupler.
    • Prevents an error condition from being raised when zero flow cannot be attained.
    • Is subtracted from measured flow when evaluating against expected flows.
  • Max low deviation (%): The maximum low deviation (1-300%) of the expected flow for the active downstream stations. This flow rule should not be enabled without running a Learned Flow program. 
  • Max high deviation (%): The maximum high deviation (1-300%) of the expected flow for the active downstream stations. This flow rule should not be enabled without running a Learned Flow program. 
  • No Flow (GPM): When 0 GPM is recorded during irrigation. This rule is automatically enabled with any active flow rule to protect a pump. 
• Delays
  • Flow Rule Start Delay (sec): How long after the controller has initiated irrigation or has measured flow (unscheduled) should it initiate a flow rule. This should be at least 10 seconds to allow for flow to record. We recommend a Start Delay of at least 30 seconds. 
  • Flow Rule Change Delay (sec): Define the number of seconds the system shall wait for a change in running downstream stations before checking for alarms. We recommend a Change Delay of at least 20 seconds. 
  • Flow Rule Error Delay (sec): Defines the number of seconds an error shall be observed before it triggers the alarm. We recommend a Change Delay of at least 30 seconds. 
• Flow Stability (Recommended to keep Defaults, used only for Learned & Verify Flow)
  • Stable Deviation (%): Defines the maximum % deviation from previous reading before a flow reading is considered stable for learn flow and verify flow. The default is 10%.
  • Stable Count: Defines the interval in counts of 5 seconds where the readings shall be within the stable deviation % for accepting the flow for learn flow and verify flow. The default is 5 counts. 
  • Stable Max (min): Defines the maximum minutes to find a stable flow before it gives up finding a stable flow for learn flow or verify flow. The default is 5 minutes.
    

For more information on Flow Rule Alarms & how to react to them, use this link:

Flow Rule Alarm Handling

For more information on building a Learned Flow program, use this link:

Build & Run a Learned Flow Program