I am currently working with the PLCnext 2152 controller and facing an issue with bit statuses. On the hardware side, the signal is being received correctly, and the module configuration status shows „true.“ However, the bit status in my program is not changing.
Additionally, I’m experiencing the same issue with newly created internal bits—their statuses are not updating even though the input side is providing a signal. When I use a single bit coil as a set coil, it is not getting set as expected.
This issue is quite perplexing for me, and I am looking for a solution.
Hi aliraza,
are your variables connected to the modules process data?
Best regards
DivisionByZero
Is any of your ladder logic showing power flow and bits turning on?
If you are offline & programming on your „Main“ program and then you go online, the ladder logic „Main“ window is not your running code – this is still your copy of the offline ladder logic.
Here is an example of the „Main“ program I was working on while offline.
image.png
If I then go online, nothing appears to change…none of these bits will show true.
In order to get the online (running) version, you have to double click on the program „version“ that is actually scheduled inside the „ESM“ tasks.
Go to your project tree and double click on this „Main“
image.png
Now when I look at the ladder logic, you should see power flow (and a green tab of the „Main“ program).
image.png
SFW
Is any of your ladder logic showing power flow and bits turning on? </p>If you are offline & programming on your „Main“ program and then you go online, the ladder logic „Main“ window is not your running code – this is still your copy of the offline ladder logic.</p>Here is an example of the „Main“ program I was working on while offline.</p>[https://forum.plcnext-community.net/uploads/LVVNB9G15U9G/image.png</a></p>If I then go online, nothing appears to change…none of these bits will show true.</p>In order to get the online (running) version, you have to double click on the program „version“ that is actually scheduled inside the „ESM“ tasks.</p>Go to your project tree and double click on this „Main“</p>[https://forum.plcnext-community.net/uploads/83LTWAZNUYC4/image.png</a></p>Now when I look at the ladder logic, you should see power flow (and a green tab of the „Main“ program).</p>[https://forum.plcnext-community.net/uploads/58WK4GJRN81L/image.png</a></p>SFW</p>
Hi Steve,
I appreciate your support!
I encountered an issue where the ladder logic bits were not highlighted in online mode, meaning the power flow wasn’t reaching the non-working bit. To resolve it, I deleted the tag and wrote a new one. However, the new tag wasn’t defined, and typically, the software should flag it as an undefined tag with a red indicator. In my case, this wasn’t happening, and the option to define the tag from the main window was not available (the „New Variable“ option was grayed out).
I manually defined the tag in the tag table, but the bit still didn’t show power flow. So, I deleted the tag again and typed the tag name on a normally open contact. Still, there was no error indicating an undefined tag. After restarting the software, the undefined bit turned red as expected, and I was then able to define the tag properly. Once defined, it worked fine.
Unfortunately, I’m having to repeat this process for every tag definition, and it seems like this may be a software bug related to tag definition. Do you have any insight into why this might be happening?
Best regards,
Ali Raza