Configure the ProtectedLocation Row Edit: Low Mode tab

Status Point

Enter or select the name of the status point used to switch the Protected Location between higher and lower operating intensities (High mode and Low mode, respectively).

Low Mode State

Enter or select the name of the status point’s low operating mode.

High Mode State

Enter or select the name of the status point’s high operating mode.

Violation

Use this section to configure the violation conditions that the Low Mode application:

• Checks when a Protected Location attempts to switch to High mode.

• Monitors when the Protected Location is in High Mode.

Path

Enter or select the path to an analog, a status, a multistate, a remote, a pump, or a valve record that the Low Mode application monitors for a high mode violation condition.

Comparison Operator

(Analog points only) Select the mathematical operator used when comparing the value of the analog point in the Path field to a Value.

Options:

• < (less than)

• > (greater than)

• = (equal to)

• <= (less than or equal to)

• >= (greater than or equal to)

  Example:

  If:

• Current value of analog point changes to "60".

• Comparison Operator is ">".

• Value is "55".

  Then:

• The application executes the Low Mode Action Sequence to switch the Protected Location back to Low mode.

  Note: if using a Comparison Operator, ensure the Threshold is zero. Otherwise, the application ignores the Comparison Operator and uses the functionality described for Threshold below.

State

Enter or select the device state that triggers a transition to Low mode (Status, multistate, pump, and valve points only).

Value

(Analog points only) If using Comparison Operator, enter a value to compare to the analog point’s current value as per the selected Comparison Operator.

If using Threshold, then 1) enter a value that results in a violation condition when the analog point’s current value exceeds it, and then 2) enter a Threshold value.

Threshold

(Analog points only) Enter a value for use in the following equation:

Value – Threshold = No Violation

When an analog point enters a violation condition, it must fall below the Value minus the Threshold in order to exit the violation condition.

Note: if using a Comparison Operator, ensure the Threshold is zero.

Timeout (s)

(Remote points only) Enter an acceptable outage duration, which, when exceeded, triggers a transition to Low mode.

Outage Reset (s)

When a remote fails a validation check, the system places it offscan. After the Controller successfully brings the remote out of the state that resulted in the violation, the system places it back onscan.

Type the amount of time that must pass before the system marks the reconnected remote as "good".

Station Search Depth

This field determines how far upstream the Low Mode application travels to switch stations to Low mode in the event of a violated condition.

Example 1:

Assume we have stations 1, 2, 3, and 4. Station 1 is the most upstream station, and 4 the most downstream. Station 3 has a Station Search Depth of "1".

The Low Mode application detects a violation at station 3. The application traverses up only one station (to station 2) and executes the Low mode sequence indicated in the Low Mode Action Sequence field below.

Example 2:

Assume we have stations 1, 2, 3, 4, and 5, with a branch from 2 to 3 as follows:

1 –- 2 –- 4 –- 5

|

3

Stations 1 and 3 are the most upstream stations, and 5 the most downstream station. Station 4 has a Station Search Depth of "2".

The Low Mode application detects a violation at station 4. The application traverses up one station (to station 2) and executes the Low mode sequence indicated in the Low Mode Action Sequence field below. Even though a depth of only one remains, the application continues upwards to both stations 1 and 3 and switches them to Low mode.

The system also makes use of the Station Search Depth field when an Controller attempts to "open" a Mode Detector point (switch it from Low mode to High mode). Normally, the system searches downstream for any Protected Locations in a violation state. In this case, the Station Search Depth field limits the number of downstream stations that it checks.

Additional considerations for Station Search Depth

• If the Low Mode application encounters a station (an fnet record) without a Protected Location, it ignores the station. The encounter in this case does not count towards the total depth traversed.

• An entry of "0" disables the functionality.

• Negative values are not permissible.

Low Mode Action Sequence

Enter or select the name of the action sequence that the Low Mode application executes to switch the Protected Location from High mode to Low mode.