how plc generates the analog signal (speed signal) to the VFD ?

[phatcreators]

I want to ask from you that , how plc generates the analog signal (speed signal) i.e. analog signal to the VFD ?

What input(s) or thing(s) are required for PLC to generate the speed signal to the VFD ?

 

[pedroromanvr]

Do you mean the input of the VFD? Normally, VFDs have serial inputs (BUS, RS-485, PPI, etc). So you can configure the PLC to send a value that would represent the speed of the motor at a given time (as well as many other things).
The VFD does all the job (initialization, startup, run, stop) based on the commands recieved from the PLC.

 

[phatcreators]

would you represent any plc programming in that fashion ? how it represents the speed of the motor