PLC

There are a couple of thoughts on this. You could connect a PLC to a VFD using a communication protocol like Ethernet IP or Modbus to name a few or using a collection of analog and digital signals. I prefer a combination of the two ideas. For command and control signals I use analog or digital signals. For all other data I use a communication protocol. The reason is that any decent technician can troubleshoot an analog or digital signal but troubleshooting a communication protocol takes a ver ...

How can I control through the VFD Torque for a motor as I have a pump motor of 110 KW of rated current 200A controlled by Soft Starter and during the actual operation it consumed only 65 KW with 98A so I want to change this motor with another one lower in KW with VFD to control at the new motor Torque, so how to do that?
If the new motor is large enough to provide the load requirements then reducing the motor size will not affect performance. It is the load that dictates torque required ...

A PLC (or Programmable Logic Controller) has traditionally been a simple general purpose computer, that can be programmed using a simpler language than those used by "computer programmers". Really what it comes down to is a single (MSDOS) versus Multi tasking (Windows/Unix) computer. A traditional PLC is basically no different than a "PC" running a script interpreter. The only real distinguishing factor is in the type of I/O available and the communications. Other "variables" include the amou ...