For the TONR, when the R is activated, are you monitoring the leading and trailing edge of the R input on the next network or rung or line of SCL?

If you are monitoring the R for leading/trailing edge, you can see if and when the ET and Q are reset, and latch that action with a SET coil or assigning a tag to TRUE.

Is that what is in your project?

MatLcq

Topic Infos:
- Windows 10 x64
- TIA Portal V15.1 Upd 4
- CPU 1518-4 PN/DP V2.5 (6ES7 518-4AP00-0AB0)

Problem:
For project purposes, I had to build a timer block with extra features, based on the TONR instruction (you can find a stripped down version of it in the attached project). This block was itself integrated within much more complex functions. Theses functions were not functioning right under certain circumstances, and I figured out that it was that "Timer" block that was the root cause of the dysfunction.

After analyzing it, I found out that the reset of the TONR instruction was not behaving like I was expecting. In the help of TONR timer for CPU S7-1500, it is stated that "The R input resets the ET and Q outputs regardless of the signal state of the start input". My tests shows a different behaviour: RESET of TONR instruction is not always complete after a pulse on the R input.

I'd like to know if this is an expected behavior, and somehow I misinterpret the help, or if this is not normal?

You can find a TEST application attached with the bare minimum to emphasize the observed behavior. Also below you can find more information about the problem and how the application and "Timer" block are build and must be used.

Thank you very much for your help.

Are you suggesting modifying the timer values while it is timing?

I did not see any problems in the provided spreadsheet image as it compares to the F1-Help for the TONR where the RESET input is level sensitive and ignores the IN input state while TRUE.

Are you saying the timer acts incorrectly with the reset applied?

MatLcq

Here is how to use the attached application (it works with PLCSim)...

In the OB1, with monitoring ON:
1) Set "Mode" to FALSE
2) Set "DbTimer".Setpoint to 3000.0 for instance
3) Set "TimerSetpoint" to 6000 for instance (something greater than "DbTimer.Setpoint" in any case)
4) Set "AlwaysSet" to TRUE to load the TONR instruction
5) Once the "FbTimer".Done is TRUE, set "Step1" to TRUE

=> "Result" should be set to TRUE

What it shows is that if a reset with the R input of TONR is done while the IN input is still TRUE, the reset of ET is not done properly, and the Q output is still set in the next cycle.

When preventing this by setting the IN to FALSE while R is TRUE, it doesn't happen, and the reset of ET is rightfully done.

You can test it by setting "Mode" to TRUE, resetting the "FbTimer" using the "AlwaysReset" bit and redo step 2) to 5) here above.

A picture of an excel file shows the evolution of the IEC_TIMER values at each cycle.
EDIT: the picture shows, for each cycle, the values of inputs, and outputs BEFORE and AFTER the timer call.

If I understand correctly, the R input is acting like the IN input is expected to act.

The IN input is supposed to keep the ET state.  

If this is V16 update 1 and latest firmware on the PLC, please submit a request for assistance from Siemens Support (create new support request).

If you are not running the latest firmware or updated TIA Portal software, see if there updates are available for either as those updates might correct any behavior that is not as described in the F1-Help and system manual.

MatLcq

 Oh, wow you're fast. No, I'm not doing that, but it seems like when R is TRUE, ET and Q are reset, but if R is FALSE the next cycle, ET and Q comes back to their previous value. But this ONLY if IN input is TRUE while R is TRUE too!!!

Check out the Cycle Number 1 and 2 of the attached picture in my previous answer, maybe it will be clearer. 

Let's NOT ignore the most likely reason you are seeing abnormal behavior.  See the attached image from F1-Help on TONR. 

MatLcq

Let's ignore the fact that I'm trying to change the TONR PT for now.

What I observe is the following:

- At cycle 0, IN = TRUE and R = FALSE, ET = PT and Q = TRUE
- At cycle 1, IN = TRUE and R = TRUE, then after the call of TONR instruction, ET = 0MS and Q = FALSE => Like it should and like stated in the F1-Help.
- At cycle 2, IN = TRUE and R = FALSE, then after the call of TONR instruction, ET = PT again and Q = TRUE => But it should not! It should be ET = ~0MS and Q = FALSE

Is that normal?

Thank you for your assistance