management of frequency inverter via the analog outputs with a time ramp

[Edvin]

Dear all,

 

have someone any application or some sample about driver control by analog output with time rump up & time rump down system.

 

[Kikis]

Hello Edvin,

 

I asked the same question a few years ago in the forum and got great feedback, so have a look on the following topic:

 

http://forum.unitronics.com/topic/1584-analog-out-with-up-down-ramp/?hl=ramp 

 

 

My application was to drive a pressure proportional valve for hydraulic control system via analog output.

 

For your application, I think that all VFD's have this feature as standard, did you check that your VFD is not capable of doing this automatically?

For example on Lenze drives, which is the VFD brand i use in my projects, you can set the total acc/dec time from the local keypad of the drive. 

So i'm just sending the analog voltage command from the PLC and the drive automatically performs the ramping of frequency. 

[Edvin]

Thank you very much..