Memory Slots

Overview

Pathfinder Core PRO's memory slots provide a named location for storing data that can be used in Logic Flows. You can create and view memory slots via Automation > Memory Slots. You can also monitor the slot’s changes in real-time and alter the value of a memory slot directly from this page.

The list shows each slot's current Value, its StartupState and StartupValue, its Type and whether it is Persistent. Type in the Search box to filter the list. When a search matches a slot inside an array, the array is shown with it.

Add a memory slot by clicking the Add + button on the bottom-right corner of the memory slot list.

The Memory Slot Editor opens over the list.

Select the memory slot type you wish to create from the Type drop-down. The available properties will change depending on the memory slot type. Several of the memory slot properties are present in all or most of the memory slots as described here.

Common Memory Slot Properties

Each memory slot may also have additional properties according to its type as described below.

Working With the Memory Slot List

Changing a Value

Click the edit icon next to a slot's value to change its current value without opening the editor.

This changes the current value only. The startup value is not changed, except when the slot's Startup State is LastKnown, where the current value is always the value the slot will start with.

When a slot's Startup State is StaticValue, a second edit icon appears in the StartupValue column. Use it to change the value the slot starts with, without changing its current value.

Selecting, Cloning and Deleting Several Slots

Tick the check boxes at the left of the list to select slots. A toolbar appears above the list with the number of slots selected and three buttons:

• Clone Selected creates a copy of each selected slot.

• Delete Selected deletes every selected slot, after asking you to confirm.

• Clear Selection unticks every slot.

To copy a single slot, click clone in its row. Memory Slot, Latching and Numeric slots can be cloned.

To delete a single slot, click the trash icon at the right of its row.

Memory Slot Types

Pathfinder Core PRO has seven different types of memory slots, each with its own options and properties.

Memory Slot

This is the traditional memory slot into which any kind of data may be stored. Its parameters are shown below:

All parameters for this memory slot are described in the common properties section above. When Startup State is set to StaticValue, a Startup Value field appears:

Latching

The Latching memory slot can only have a value of True or False. It has a write-only property called Trigger which will change the memory slot's value. Using a Logic Flow end-point, you can set the trigger property to true and the slot value will toggle from true to false, or from false to true depending on its current value. See the latching example in the Logic Flows section of this manual for more details. The configuration properties for this slot type are shown below:

All parameters for this memory slot are described in the common properties section above. However, note that the value and startup value property fields become drop-downs that only allow a value of True or False.

Numeric

Numeric memory slots allow you to store, retrieve, increment, and decrement a numeric value. Its write-only properties, listed below, can be used in Logic Flows to change the value of a memory slot. This type of memory slot can also accept a range to specify what happens when the value increments or decrements outside of the range using the loop action option. Its parameters are shown below:

In addition to the properties outlined in the common properties section above, this memory slot type includes two additional properties: Range and Loop Action. If the range field is left blank, then the numeric memory slot may accept any numeric value. If you apply a range by filling the range field with a low and high value separated by a hyphen, then increment and decrement will not exceed the specified range. The Loop Action property only works in conjunction with a range and does nothing if no range is specified. The loop action field defines what happens when you try to increment or decrement beyond the specified range as follows:

• None = Incrementing beyond the max or decrementing below the min will do nothing and no change will be applied to the Value.

• Forward = Incrementing beyond the max will cause the value to loop back to the min, but decrementing below the min will make no changes.

• Backward = Decrementing below the min will cause the value to loop to the max, but incrementing beyond the max will make no changes.

• Both = Incrementing beyond the max will cause the value to loop to the min value, and decrementing below the min value will cause it to loop to the max value.

These properties make it easy to assert a valid range to a numeric memory slot as well as to implement things like paging functions where paging beyond the maximum number of pages will take you back to page 1.

The Value and Startup Value fields only accept numbers.

Write-Only Properties

Numeric memory slots have write-only properties that Logic Flows can set to change the slot's value. Each one takes the value written to it:

SapProperty

SapProperty memory slots allow you to map the value of any Sap Property in the system to this memory slot's value. When this Sap Property value changes, the slot is updated with that value. Its configuration parameters are shown below:

In addition to the properties outlined in the common properties section above, this memory slot type includes two additional properties: Object Path and Property Name. The ellipsis button next to Object Path can be used to select the Sap Property to be used with this slot and when selected will present a property selection dialog similar to that of the dialog in Logic Flow endpoint editing. Once a property is selected, the object path and property name will be filled in based on the dialog selection.

The value and startup state properties are not present in the configuration as the value gets filled dynamically over time according to the value of the selected Sap Property. This value is then available to be used with Logic Flows. It can also be used to create custom values when used in conjunction with the String Builder memory slot.

String Builder

The string builder slot allows you to build a string based on values in other Memory Slots. The parameters that will be presented when selecting this type of memory slot are shown below:

In addition to the properties outlined in the common properties section above, this memory slot type includes two additional properties; Included Slots and Pattern. The Included Slots field is used to enter a comma-delineated list of memory slot names to use in the builder. The ellipsis button will present a list of slots to select from. The order is important as described by the Pattern. The Pattern field is a text pattern with bracketed numbers used where slot values from the comma-delineated list should be inserted.

In the example above, case {0} will be replaced with the value of SlotA and {1} will be replaced with the value of SlotB. If SlotA’s value is "Fred" and SlotB’s value is "Telos Alliance", the value of this new memory slot called MyBuiltSlot would be: The Name is Fred and it is located at Telos Alliance. The value of this slot will update whenever SlotA or SlotB updates. This slot can be used to build text which is then used as labels on buttons or commands to generic emulators. When the included slot list contains slots that are Sap Property Memory Slots, this memory slot type can become even more powerful.

Time Stamp

The Time Stamp Memory Slot can be used to grab time stamps, which can be useful in displaying the last time something happened in a user panel. The parameters that will be presented when selecting this type of memory slot are shown below:

In addition to the properties outlined in the common properties section above, this memory slot type includes one additional property: Pattern. When you first create a time stamp memory slot, you will probably not apply a value. The pattern field can also be left blank, in which case the system's default date and time format is used. It can be used to specify the format of the time stamp which we will describe in more detail below.

Time Stamp memory slots have three write-only properties that Logic Flows can set:

After creating the timestamp memory slot, it can be used in Logic Flows by applying an endpoint to the SetTimeStamp write-only property of the memory slot. For example:

This Logic Flow will set the memory slot to the current date and time every time the specified GPIO pin goes low.

The time stamp memory slot can also be used to convert values from one time format to the pattern specified in the time stamp memory slot. This is accomplished using the write only ConvertTimeStamp property. For example, you could assign a number with either m, h, or s to the end, and it would convert the value to the requested format in minutes hours or seconds. If the time stamp memory slot pattern was:

hh:mm:ss

and you passed in

100s

to the ConvertTimeStamp property, the value of the memory slot would become 00:01:40.

Passing other time values than just numbers will try to interpret the value as time, convert it, and then express it in the correct pattern.

Array

An Array memory slot holds a group of memory slots, called members. Each member is an ordinary memory slot of any type, including another array, so arrays can be nested. Use an array to keep related slots together, such as every slot that belongs to one studio. A Logic Flow, User Panel or third-party application that subscribes to the array receives every member, at every level, through that one subscription.

To create an array:

1. Click Add + below the list, choose Array Memory Slot as the Type, and type a Name. An array has no value, persistence or startup settings of its own, so these are the only fields.

2. Click Apply. The array appears in the list, empty.

3. Click the array's edit link. The editor now shows a Members panel with the array's path.

4. For each member, choose its type from the drop-down below the members (Memory Slot, Latching, Numeric, SAP Property, Text Builder, Timestamp or Array), type its name, and click + Add Member.

5. Use Edit to set a member's value and other settings, or Del to delete it, then click Apply.

Once members have values, the editor shows them in the members table:

Members are created inside the array: an existing slot cannot be moved into an array.

In the list, an array shows the names of its members. Click the arrow next to an array's name to show or hide its members, which can be edited like any other slot.

Some rules apply to arrays:

• An array is always persistent, and its Startup State is always LastKnown. Its members keep their own Persistent and Startup State settings.

• An array has no value of its own; in the list its Value column shows its members' names. Writing a value to the array writes that value to every member.

• A member's name only needs to be unique within its array.

• Deleting an array deletes all of its members.

Startup State

The startup state drop-down applies to each of the memory slot types above except SapProperty, and requires some explanation. This option allows you to determine the value of the slot when the system first starts up and before any flows are executed. It can be:

• Blank: blank.

• StaticValue: a fixed value as defined in the slot's Startup Value.

• LastKnown: last known.

It is important to understand the last known option will attempt to store the state in the database each time the memory slot state changes. This can be more CPU- and time-intensive because of the storage within the Pathfinder Core PRO. As a result, this option should not be used in situations where the existing state of Axia devices will reset the memory slot to the correct state via the flows as the flows start-up anyway.