by using 1215C, I have a proportional valve work with 500Hz and according to signal duty cycle it control spool position. 

so i need to set frequency of PWM at 500 Hz Fixed frequency and control its Duty cycle. 

is it available to set frequency of PWM to 500Hz with controllable duty cycle??

if not, any other CPU can support this function??

0_Einstein

What you describe in words is pretty much the definition of Pulse Width Modulation.  Establish the pulse frequency, and then vary the width (duty cycle) of those pulses.

So yes, the s7-1200 can do that - provided you do not have a RLY output PLC. 

MAdel924

by using 1215C, I have a proportional valve work with 500Hz and according to signal duty cycle it control spool position. 

so i need to set frequency of PWM at 500 Hz Fixed frequency and control its Duty cycle. 

is it available to set frequency of PWM to 500Hz with controllable duty cycle??

if not, any other CPU can support this function??

 

Thank U, to be more clear for me:

- I must use 1215C DC/DC/DC

- I can control duty cycle with a certain frequency (ex: 500 or 400Hz or ..... less than 100KHz)

- to get variable frequencies; duty cycle will be 50% (fixed).

MAdel924

 Thank U, to be more clear for me:

- I must use 1215C DC/DC/DC

- I can control duty cycle with a certain frequency (ex: 500 or 400Hz or ..... less than 100KHz)

- to get variable frequencies; duty cycle will be 50% (fixed).

 

Do you want to control duty cycle or frequency?
The S7-1200 does not allow you to do both at the same time.

The hardware configuration is used to configure either PWM or PTO.

Control in code is achieved by the instructions CTRL_PWM (Pulse width modulation) or CTRL_PTO (Pulse train output). See the instruction help in the software for details.

Attached is a screenshot of a possible PWM configuration and some user manual pages of how to use the CTRL_PWM instruction.

Getting hold of the System Manual is a very good idea.
https://support.industry.siemens.com/cs/ww/en/view/109772940

qwazee

 

MAdel924

 Thank U, to be more clear for me:

- I must use 1215C DC/DC/DC

- I can control duty cycle with a certain frequency (ex: 500 or 400Hz or ..... less than 100KHz)

- to get variable frequencies; duty cycle will be 50% (fixed).

 

Do you want to control duty cycle or frequency?
The S7-1200 does not allow you to do both at the same time.

The hardware configuration is used to configure either PWM or PTO.

Control in code is achieved by the instructions CTRL_PWM (Pulse width modulation) or CTRL_PTO (Pulse train output). See the instruction help in the software for details.

Attached is a screenshot of a possible PWM configuration and some user manual pages of how to use the CTRL_PWM instruction.

Getting hold of the System Manual is a very good idea.
https://support.industry.siemens.com/cs/ww/en/view/109772940

 i just need to control duty cycle at fixed frequency 500 Hz??

MAdel924

 i just need to control duty cycle at fixed frequency 500 Hz??

Good. Then you have what you need from the material I have given you.