https://forge.codesys.com/forge/talk/Engineering/thread/3d0996850b/2020-11-09T06:16:38.097000ZRecent posts to How to make the output of a function blok persistent?2020-11-09T06:16:38.097000Z2020-11-09T06:16:38.097000ZdFxhttps://forge.codesys.com/u/dfx/https://forge.codesys.come0ca8fd11a6a4d5a29399a8a0169a8a93eb63c3c

<div class="markdown_content"><p>Using an inout variable will suit your requirements.<br/> More generally, if you need to know the previous state of an output variable, then it should be an inout. Inout refers to variables you want to read and write.<br/> Just define the inout variable as persistent.</p></div>

2020-11-07T13:02:56.198000Z2020-11-07T13:02:56.198000Zbenbammenshttps://forge.codesys.com/u/benbammens/https://forge.codesys.comc5303d5677ec5c854a98fc265d6fdbaca0f25f2d

<div class="markdown_content"><p>Hello,</p> <p>I use a PFC200 with codesys for my home automation. I would like the light outputs to be persistent since it is a pain in the b... that every time when I re-upload the program or restart the PLC the lights go out... </p> <p>I use push buttons an a toggle function block to control the lights. I have made the final output variable persistent, but when the program starts, the output "Q" of the toggle FB gets reset ofcourse and the light is switched off. </p> <p>I have tried to define the entire block as retain variable but this does not seem to work. I cannot define the "Q" as retained in my POU since it is part of the FB... </p> <p>Is there an easy way to set this up? </p></div>