PowerFlex 40D Variable Frequency Drive (RS485 communication wiring)


I have a PowerFlex 40D Variable Frequency Drive and I want to control it with Arduino. I'm really confuse of where to connect the two wires (+ and -) of the TTL to RS485 module to the VFD terminals. Here is the manual of the VFD:


The information about RS485 wiring can be fount at page 149.

Some help with this?

Usually + is connected to A, while - is connected to B. As you forgot the link to the TTLtoRS485 adapter I have no clue about the names of the pins in your case.

Thank you! You can find in the attachment a presentation of the module.

As I said: A to +, B to -, don't connect any of the other pins to the PowerFlex (this includes GND!).

Thank you pylon but that is my problem. I don't know on what terminals to wire A and B. I don't have any terminals with + and -. Take a quick look in the linked manual at page 149. But quite important anyway that you specified not to put grounds in common.

On the picture in the lower part of page 149 you see two pins called TxRxD+ and TxRxD-. Remove the "TxRxD" prefix and you have '+' and '-' pins. I don't see the problem.

Thank you! I just wanted to be 100% sure so I don't damage something.