Memory Module

The Memory Module is used to store a value received on the Input connector and send it to the output only when a dedicated trigger condition is activated.

The value received on Input is stored internally by the node, but it is not immediately propagated to the output.
The stored value is sent only when the Save Trigger input is activated.

The Memory Module separates the acquisition of a value from the moment in which that value is sent to the output.

The basic sequence is:

• a value is received on Input;
• the value is stored internally;
• the output remains unchanged;
• when Save Trigger = 1, the currently stored value is copied to Output 1.

Conceptually:

Input → Internal memory

and, when:

Save Trigger = 1

then:

Output 1 = Stored value

Assume the following sequence:

The value 444 is stored and sent to the output only when the Save Trigger is activated.

After that, even if the input changes to 500, the output remains 444 until another Save Trigger is received.

The node always keeps track of the most recent value received on Input.

For example:

• Input receives 10;
• Input then receives 20;
• Input then receives 30;
• Save Trigger is activated.

The resulting output is:

Output 1 = 30

because 30 is the most recent value stored at the moment of the trigger.

The Save Trigger input determines when the stored value must be copied to the output.

When:

Save Trigger = 1

the node sends the currently stored input value to Output 1.

The trigger does not modify the stored value itself; it only transfers the current stored value to the output.

The Memory Module is useful whenever a value must be captured and reused later.

Typical applications include:

• storing a setpoint only when a save command is received;
• memorizing a sensor value at a specific moment;
• capturing a value before starting another logic sequence;
• freezing a changing analog value until a new save command arrives;
• storing a reference value for later comparison;
• memorizing KNX values only when explicitly requested.

Suppose a variable setpoint is connected to Input.

While the user modifies the setpoint, the value on the input may change several times.

The output, however, remains unchanged.

When the user confirms the desired value by activating Save Trigger, the current setpoint is copied to Output 1.

For example:

The value 22°C is therefore saved only when the trigger is received.

The Memory Module can be tested using the Logic Module simulation tools.

A typical test procedure is the following:

• connect a variable value to the Input connector;
• connect a digital signal to Save Trigger;
• start the simulation;
• change the Input value several times;
• verify that Output 1 remains unchanged;
• activate Save Trigger;
• verify that Output 1 takes the current stored value;
• change the input again;
• verify that the output remains unchanged until the next trigger.

• The most recent value received on Input is stored internally.
• Input changes do not immediately affect Output 1.
• Save Trigger copies the currently stored value to the output.
• Use the Memory Module when a value must be updated only on demand.
• The value type used on Input should be compatible with the connected destination on Output 1.
• If the input changes several times before the trigger, only the latest stored value is sent.

• Logic Module
• Logic Module - Simulation management