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GX Works3 FX5U - Adroit - Memory Device Retention (Latching)

GX Works3 FX5U - Adroit - Memory Device Retention (Latching)

Introduction:
This is a short article explaining how to configure memory Device Retention (aka latching) on a Melsec iQ-F PLC - via GX Works3.
From here - the PLC is being interfaced with Adroit SCADA to demonstrate the device retention concept.

The Process Procedure:
The following applies;
A Battery is required for retention purposes;

The Super-caps are insufficient, not connected

The Device/Label Memory Area Setting

In this example - we will be setting the data register range (D) for retention

Latch Range settings for - latch (1)

Latch Range settings for - latch (2)

The Difference between Latch 1 and Latch 2:
image

The final product after the latching:

As for the programming itself

  1. IF the values are manually entered – and retained by the PLC – then the above settings are sufficient. (Static values – like parameter coefficients, constants)

a. Attached sample program demonstrates this.
GX Works3 FX5U - Adroit - Memory Device Retention (Latching).gx3 (632.0 KB)

  1. IF the values to be retained are as a result of a Function Block output (like counters and timers) – then additional programming is required.

a. Retentive value to be moved to the FB Output value at PLC startup.
b. Attached Sample program demonstrates this

An example:
The following is a demonstration example;

Demonstration Videos:
GX Works3 - setting up - latching of dynamic values (counter values)

GX Works3 - Setting Up - Battery Backed up - Retention Latching

GX Works3 - Demonstration of Counter value retention between Adroit SCADA and PLC

Resource Reference:
The following reference information is applicable:
Proof of Concept Demo
Attached - PLC Program sample:
GX Works3 FX5U - Adroit - Memory Device Retention (Latching).gx3 (632.0 KB)

Attached - Adroit SCADA sample:
GX Works3 FX5U - Adroit - Memory Device Retention (Latching).zip (35.9 KB)