In one of my applications i want to control the VFD of danfoss make VLT5000 series through PLC through serial communication. please suggest how to do this? or give any application note on danfoss serial communication with any PLC.

 

Danfoss have a modbus card available that plugs into their VSDs.
Danfoss also have released full details of their protocol and it is quite simple to write a driver.

 

GE PLC support only modbus as a slave, so VFD of danfoss should be the master on the modbus link.

 

GE can also talk DeviceNet and Profibus, Profibus being the preferred method because of its higher speed. Devicenet will only talk to drives in 8 bit bytes, and usually the VFD manufacturer will only provide 4 bytes of info standard in its default call. All other info must be addressed from PLC using Implicit messaging, which is a pain to program and ties up the network. Profibus is fast and robust. Serial is...basic, and usually used for monitoring, not control.

Why Danfoss? Other manufacturers make drives specifically designed to work with PLC communication highways.

 

Please contact me at this e-mail address as I have some application notes on how to set a VLT 5000 up with differents PLC.

[email protected]