Mitsubishi FR-F700 & arduino

Hi All,

briefly, here' my problem :

i own a VFD mitsubishi FR-F700 and i want to pass the frequency or the amperage from the arduino uno ?

(using the potentiometer or RS485 or directly from the arduino board )

someone has a clue ?

thank you

From a quick overview of the manual (, BTW you should have provided that link!) it seems that the inverter is the ModBus RTU protocol on the RS-485 bus (4-wire variant). So you should get a 4-wire RS-485 shield or breakout (I know only of 2-wire variants commercially available) and use one of the ModBus libraries available.

Please allow me the question: Do you really know what you're doing? This inverter is for handling high voltages and judging from your post it doesn't seem that you have experience with that. There is a high risk of hurting yourself.


thank you for your reply and concern , i know that it has a little risk, what i want to do is to control the speed of a motor via vdf and arduino, i did an experience with the potentiometer and it work, what i want is if there's a way to do that from arduino directly without using the potentiometer ? (because i notice that the mitsubishi can read the pression value from a nanometer , so i could simulate that value with arduino analogue signal output)

if not, i'll give a shot to use a RS485 shield :

what your think ?

thank you

The Arduino UNO does not have an analog output and I'm not sure if the inverter will be happy with a PWM signal.

The RS485 board behind the link is not suitable for this inverter because it only supports 4-wire RS485 (fullduplex) and this board is a normal 2-wire variant (half-duplex). I found a shield that does support fullduplex communication but only with RJ-45 connectors on it:

Another board is this here (but I don't understand the description):

A even better solution might be this one:

because it also provides a GND connection that seems to be needed by the inverter.

thank you very much pylon , you're solution is very useful. thank you