PLC download problem

[Luka0204]

Hi,

when I download on PLC (R04), sometimes for example. TON timer's output .Q is automatically set to true even though input is false (also on .ET time is 4h ...??). Also, sometimes some bool variables are also set to true even though they are not set by any kind of logic.

However, when I physical reset the PLC (power cycle), mentioned problems don't exist. Does it mean that software reset isn't working entirely correct and I need to reset physical PLC (power cycle) every time after I download on PLC?

Regards

Luka

[Crossbow]

Never seen such...  What software?  What PLC?

[Inntele]

The situation is really strange. While... Is the program written in STL language? The cause might be there...

[Veganic]

The answers are in the program - You would have to upload it here though.

:)

Edited November 20, 2018 by Veganic

[kaare_t]

If you're using labels, and make big changes then there might be that the devices "shift" so to speak (if you insert code in between other lines of code, then e.g. T100 shifts to T101 which was previously 'ON' and holds this state in the next transfer). I'm not sure if you are using labels, but they are automatically assigned to actual addresses in the CPU, and when injecting code in between other lines of code, devices can "change place" (if not specified in GVL). Further, when you reset your CPU (by power, or remote reset), all devices are reset (set to zero), and the problem "disappears".

Again, I'm not sure what you're using, but if you are using labels this is my guess.

Further, I would recommend you to start using "Online Data Exchange" (or what it's called) which injects your new code on-the-fly without the need to recompile the complete code, or to 'STOP' the CPU whilst transferring code. It's a lot faster than to continously download new code, and it doesn't reallocate labels during runtime. Check it out