VFD to PLC

[ssali]

HI.
 
I wanted to know how to connect a VFD to a PLC.
I am sorry for very basic questions, but i have never used this equipment before.

Thanks in advance.

Sara.

[support]

Are you referring to Vacuum Florence Display or Variable Frequency Drive (also called frequency inverter)?

If it is the Vacuum Florence Display and conforms to Hitachi HD44781 interface then it can be attached to the PLC's LCD port.

If you are referring to frequency inverter, then it depends on what kind of interface is available on the VFD itself. It could be an analog input, PWM input or serial RS485 inputs. The T100MD+ PLC is able to interface to any of these interface. The PLC has two channels of 0-5V analog outputs that can connect to the VFD analog input and it is also able to send/receive ASCII or binary data via its RS485 port, which makes it possible to interface to VFD via serial interface easily and accurately.

[ssali]

Hi.

Thanks for the quick reply.
I am using a DELTA VFD-M drive (variable frequency drive) and a DL05 PLC.
the PLC has two ports and the VFD has one.
So thats all I gotta do? RS485?

Thanks,

Sara.

[ssali]

one more question,
to connect it to my PC, i can just use the second RS485 port on the PLC?

thanks,

Sara,

[support]

The PLC has one RS232 port and one RS485 port. You can connect the RS232 to the PC and the RS485 port to the VFD (assuming your VFD has RS485 - please verify with the supplier of the VFD as we are not in a position to advise what's on a third party product).

[ssali]

Hey,

I checked, my PLC has two RS232 ports, and the VFD has one RS485.

Thanks,

Sara.

[support]

I thought you are referring to our PLC (Please note that this forum is for supporting TRI PLC products ONLY). If your PLC is not a TRi PLC products whatever I said above may not work and we are not responsible for making your other PLC work with a VFD.

You can post general PLC questions to the "General Discussion" area. For questions to be answered here it should be a TRi PLC related questions.

[ssali]

I know and I understand that.
I am learning using your software before I buy the PLC. This one was handed to me for the time being, becuase they had it in storage.

[sandwich]

A typical installation has the plc sending a 120 volt run signal. The vfd then returns a 120 volt signal back to confirm that its running. So you need one input and one output.

The drive can be programmed for speed, ramp up time, etc. You can change the speed using the vfd display or a remote speed pot.

[philipjoseph]

If you check
http://www.tri-plc.com/yabbse/index.php?board=1;action=display;threadid=1345
I waas able to communicate the PLC t100MD with a VFD via MODBUS (rs485). If your VFD support Modbus you should be able to control the VFD via Modbus.

Philip