Hi Everybody!

I have a problem when made a Datalog for an Interger tag using trigger bit.

I set "Logging acquisition mode" of this tag is "On demand"

I created an another boolean tag, and set  event -> change value -> LogTag -> interger tag

When simulated by PLC sim, i changed the value of bool tag from 0 to 1/ 1 to 0, it didn't work, no record found.

But if i used a button, and set fuction "Logtag" for this, it worked fine.

So someone can give me a solution for this?

Thanks a lots.

How did you change Bool?

Is the Acquisition cycle of this Bool: Cycle continuously?

Best regards,

Wizard

 I changed the bool tag by click on the PLC SIM, and yes: this bool is Cyclic continously.

Do you use an internal Tag for the Boolean Trigger Tag. Then a safety function of the WinCC flexible Runtime could be the problem.

I you use the Value change Event of an internal Tag is not executet if you change the Value of the Internal Tag over Systemfunction, Script or Simulation. Only in EA Field it works.

(Its to prevent Endless Loops)

If you use an external Tag it Should not be that Problem.

Bye Murof

Ok, this is an external Tag and control by PLC. My project include PLC S7-315, CP343, and PC-HMI, connect over Ethernet.

I use PLC SIM to simulate and evrything is ok, but a bool tag to logging value an another tag not work.

Hi Everybody!
I have the same problem. Someone know one solution?

I dont know why, but I needed utilize the bit created in HMI tags on some screen.
If I dont utilize this tag in some screen the values of variable do not save in datalog.