Switching between digital and analogue

Hi,

Does anyone know how in my step 7 program I am able to switch between digital mode when controlling a pump and analogue mode when controlling a pump. For example in my program I am doing xyz when in digital mode but I want to be able to switch to analogue mode without an interference from the digital mode.

regards

JImbo

Hi

Please give more information.

Is pump controlled by inverter or it is on/off via contactor?

What exactly You want to achieve?

i.e. pulse control for demand 0...x and variable speed control for demand x...max?

Regards

Piotr

Hi,

the pump is either on/off or variable 0-10V by analogue control, Which I can do I want to know if its possible to make these not interfere with each other when switched to the other.

jimbo1234

Hi,

the pump is either on/off or variable 0-10V by analogue control, Which I can do I want to know if its possible to make these not interfere with each other when switched to the other.

 Hi,

I am not sure what do you want to do.

I assume you have  a VFD and you want to operate it in either Manual mode(On/Off & user defined speed SP) or Automatic mode(On/Off & external PID give speed SP). You have to use an FB manage the Motor modes, and gives start stop telegram to the VFD. The speed reference can be sent separately to the VFD. Many variation. What HW do you use?

Plenty application example up here. Any help you need come and ask!

Hi

Yes that is pretty much what I want to do,  I have written a program for both ON/OFF and analogue control but I am struggling to put them into FB and then two call them in my OB1. 

regards

jimbo1234

Hi

Yes that is pretty much what I want to do,  I have written a program for both ON/OFF and analogue control but I am struggling to put them into FB and then two call them in my OB1. 

regards

 hi,

About seting up block IOs, block calls read this:

https://support.industry.siemens.com/cs/ww/en/view/45531551