PWM control CPU 1512C-1 PN

Hi,

I don't know how to set frequency and duty cycle of build in PWM on 1512C. I know it's done by setting some of QW or QB addresses but which ones? (Manual and TIA doesn't help much)

Hello Nostradaster,

I will give you my example of PWM usage:

Well , for PWM I'm using PULSEGEN, FB43 in classic SIMATIC step 7 take a look picture:

Input CYLE(my variable #T_CYCLE) is CALL cycle in DINT format in milisec. Means if you call your block inside Ob35, and Ob35 is cycle interrupt each 20ms, T_CYCLE := 20. This is how you get it inside OB35

L     #OB35_EXC_FREQ
ITD
T     #T_CYCLE

Input INV (my variable #TimeDurationCalc) is REAL data type and it is my value , which actually controls my outputs. Its range is from -100.0 to the 100.0

Input PER_TM(my variable #CycleTime) is TIME data type and it is #CycleTime := t#2s in my case.

In the case TimeDurationCalc := 50.0, outpput Q_POS will be active 50% out of 2sec, and that is 1 sec. Q-NEG will be false

In the case TimeDurationCalc := -50.0, outpput Q_NEG will be active 50% out of 2sec, and that is 1 sec.Q-POS will be false.

Input PER_TM(my variable #CycleTime)  you should choice regarding the process you are trying to control.

Take a look attached picture:

Look in the hardware manual under extended intructions.

The default addresses are QW1000, QW1002,QW1004,QW1006

Nostradaster

Hi,

I don't know how to set frequency and duty cycle of build in PWM on 1512C. I know it's done by setting some of QW or QB addresses but which ones? (Manual and TIA doesn't help much)

 I really really feel sorry for you and what you will have to go trough with absolute garbage of instruction and manuals. What a complete and total nightmare.

Out of curiosity I looked at the manuals to look for answers and it is reminiscent of the TM modules with a set of convoluted instructions that are scattered across several manuals with very few examples and in this case there isn't a single relevant example that I could find.

And the search in this forums resulted in the usual links to manual and read this or that page.

This thread will give you the closest you will get to an answer.

What I would do is this:

Go to this link and download Library with PLC data types (LPD).

The "LPD_typeTMPulseControlCh" found i the library under folder Types>LPD>ET200SP>TMPulse

looks like it has the same structure as the control interface. The feedback data type is likely to be similar the one you will need for feedback but  I haven't looked.

You use that data in a DB or instance DB and using bit masking you set the values for the tag you want and then you use a MOVE (in ladder or assignment in SCL) to address the outputs.

The output address is set in your hardware configuration of your CPU and I believe the default for PTO/PWM1 is bytes 78-89.

I haven't tried it myself but that's how I believe it should work.

Good luck