Hello.

The attached code demonstrate how one timer block could be used for program sequencing. Rename the file from "TimedSteps.scl.txt" to "TimedSteps.scl" before attempting to import the code block into Step7.

The #code tag is an array that stores the frequency of the note while #times stores the delay for each individual step. The #code tag could be replaced by something else like a bit field that can be used to trigger individual outputs.

Another approach would be to have a fixed time between steps. Call it a sampling rate. This principle can be seen in the encoding and decoding of MP3 music (original versions). When keeping a note you only need to cover more steps.

BR

Ok so I'm still here at the same problem.

I tried a different way to write the program, based on the old structure.

I created a FB with the "Add_Time" block (here I set the time between each output, ex 500 ms wait till the next output), the TON timer and the TP timer(duration of the next output to be active, 200 ms).

After this, in the song block(FC), I put the above mentioned block where it suppose to be.

I arranged everything without any errors, works ok. 

But when I activate the input button of the plc, those outputs I set, Q1 and Q2 are constantly on.

In the monitoring screen it does what I need, but outside, on the box, does not.

I'm still stuck here and I don't know what else to try...

Overall, I'm trying to write a program to activate specific outputs at interval and duration time that I set.

Ex: 500 ms between each output, and every output is active for 200 ms, then go to the next network and do the same, but activates another output, and so on.

Thx for help!

Hi,

I thought your project was a litlle interesting, so i sat down tonight and wrote a rough example the way i would have dealt with it(if i understand correctly what you are trying to do)

I'm new to siemens too, so my code might  well be far from ideal and possibly inefficient, but i have simulated it ok.

i have one 'song' datablock that consist of the current song, and a menu of 10 songs, each song 100 steps max lenght. each step has 7 notes which can all be turned on or off for that particular step (7note polyphony).

i have one function block that deals with playing the current song. 2 timers are used, one for note duration and one for pause between steps.

You could easily update the datablock to carry different values for the times for each step--> pause and note duration could relate to each step.

I have TIA V15 update4 and used an S7-1214 for the example, attached the zipped project

let me know if there is an easier way to share the project.

Frank

 Did any of the contributions you received for this help you? Would be nice to get an update...

Another common approach when you have multiple timers is to simply have a single counter variable that counts milliseconds, constantly ascending.

To "start" a timer, just take the current counter value, add the time to elapse and store that amount in a variable.

Periodically compare the global counter to the value you have stored, and when it exceeds it, your timer has "elapsed".

This provides an almost unlimited number of timers.

However, at some point the global timer register will overflow or wrap-around.  How long this takes will depend on the data type you are storing.  You need to take some precautions for this, if the machine never gets stopped and restarted in less time than the full range of your counter.