Post by caspershes on Checking the device tree, not just the code: what else is worth a static check? ^{CODESYS Forge talk (Post)}
I spend most of my time reviewing other people's CODESYS projects before commissioning, and two kinds of defects keep showing up. Both compile clean. Both read fine. One is in the code. A pause timer whose own input gets cleared inside the branch the timer is supposed to gate: rampDelay(IN := run_2); IF NOT run_2 OR rampDelay.Q THEN run_1 := TRUE; run_2 := FALSE; // the timer's own input, cleared right here ELSE run_1 := FALSE; run_2 := FALSE; END_IF Next scan IN is FALSE, the timer resets, the condition is true again, and the second pump starts immediately. A 30-second ramp delay that actually lasts one task cycle. The setpoint is on the HMI, the operator turns it, and nothing changes. The other is not in the code at all. On one site the outdoor temperature read 0.0 °C in mild weather. The ST was correct, the variable was bound to the channel — but the channel's sensor type was left at "disabled", so nothing was ever digitised. Same class: a module with Disable_module = TRUE, or an analog output bound to a variable while its mode is off. Nothing in the project reports any of this, and the code review never looks there, because the configuration lives in the device tree and not in the POUs. That second class is what pushed me to parse the .export format rather than PLCopenXML alone — the export carries the device tree and the visualization, so "nothing ever writes this alarm variable" stops being a guess and becomes a fact you can check against the screen bindings. Three things about the format that cost me time, in case they save you some: the same device parameter can appear three times (template, internal copy, actual configuration) — the last occurrence is the one in effect; the enum value of a parameter is not in the parameter itself, it is one level down in BaseType/Value; a channel counts as used when a variable is bound to SensorValueN.SensorValue — InputStatus is a bad indicator, people deliberately bind it on spare inputs. So the question. What else would you check automatically, given both the code and the device tree? I am collecting rules from sites, not from style guides, and the configuration side feels largely unexplored. For what it is worth, the checker I use for this is free and runs offline (single exe, no install, nothing uploaded anywhere): https://github.com/caspershes/plc-lint — 43 rules at the moment, reads .export and PLCopenXML. Happy to add rules people here suggest.
Last updated: 2026-10-27

Post by shooxplc on How to call the same program from library and get the vars updated. ^{CODESYS Forge talk (Post)}
Hi, I am writing to you today because I would like to create a library that would contain a program with its various subprograms, in my example "PLC_PRG" with "a", "aa", "aaa". But once the library is created as shown below: I would like to be able to drag and drop my folder as many times as I want (let's say I manage the same system multiple times). Once the drag and drop is done, we can see the second folder with the variables renamed successfully. As shown below: But my variables in CAD_1 remain the same as for CAD, so it's PLC_PRG instead of PLC_PRG_1, for example. Is there a solution to automate this? I wouldn't want to have to rename all my variables manually, considering that in the program where I want to do this, the number of variables is substantial. Lucas.
Last updated: 2023-08-23

Sort by relevance or date